OOP第二次作业分析

前言：　　

一、知识点总结：

  本次分析的题目涉及到的知识点是Java类与对象的设计、继承与多态、接口、链表的实现以及Java基础语法的应用。

二、题量及难度分析：

  此次分析的题目集为PTA题目集04-7-3、题目集06-7-2、链表、期中考试题目集。题量和难度适中，但是需要设计的类比较多，需要设计的方法也比较多，写程序需要花费的时间比较长

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源码设计与分析：

题目集04—7-3：点线形系列3-三角形的计算

源码设计及解释：

本次源码设计我没有设计类，归根结底还是那时没有养成这种编程的风格，但是应有的方法还是很全面的，根据题目所讲，我们所设计的算法应当还要涉及到数学知识，比如关于三角形类型的判断，射线法的应用，值得一提的是，编程时关于三角形面积的求法我个人认为应该用海伦公式，简单清楚又明了，下面附上源码。

import java.util.Scanner;

public class Main {
    static double x1 = 0;
    static double y1 = 0;
    static double x2 = 0;
    static double y2 = 0;
    static double x3 = 0;
    static double y3 = 0;
    static double x4 = 0;
    static double y4 = 0;
    static double x5 = 0;
    static double y5 = 0;
    static boolean flag = false;
    static double center1 = 0;
    static double center2 = 0;
    static double same1 = 0;
    static double same2= 0;
    static double same3 = 0;
    static double same4= 0;
    
    public static boolean LocalCheckInputIegitimate(String alp) {//庞大的判断合法性的方法
        int length = alp.length();
        int comma = 0;
        int space = 0;
        for(int i = 0;i < length;i++)
        {
            if(alp.charAt(i)==','||alp.charAt(i)==' ')
            {
                if((flag==true&&alp.charAt(i)==',')||(flag==false&&alp.charAt(i)==' '))
                    return false;
                if(alp.charAt(i)==',')
                {
                    comma++;
                    flag=true;
                    if(i<length-2)
                    if((alp.charAt(i+1)==','||alp.charAt(i+1)==' '||alp.charAt(i+1)=='0')&&(alp.charAt(i+2)>='0'&&alp.charAt(i+2)<='9'))
                        return false;
                }
                if(alp.charAt(i)==' ')
                {
                    space++;    
                    flag=false;
                    if(i<length-2)
                    if((alp.charAt(i+1)==','||alp.charAt(i+1)==' '||alp.charAt(i+1)=='0')&&(alp.charAt(i+2)>='0'&&alp.charAt(i+2)<='9'))
                        return false;
                }
            }
        }
        if(comma!=(space+1))
            return false;
        for(int i = 0;i<length;i++)
        {
            if((alp.charAt(i+1)==','||alp.charAt(i+1)==' ')&&i!=length-2)
            {
                if(i+3<=length-1)
                {
                    if(alp.charAt(i+2)=='0'&&alp.charAt(i+3)=='0')
                    {
                        return false;
                    }
                }
                if(alp.charAt(i)<'0'||alp.charAt(i)>'9')
                {
                    return false;
                }
                i++;
            }
            else if((alp.charAt(i)<'0'||alp.charAt(i)>'9')&&(alp.charAt(i+1)<'0'||alp.charAt(i+1)>'9'))
            {
                    return false;
            }
            else if(i<length-2)
            {
                if((alp.charAt(i+2)!=','&&alp.charAt(i+2)!=' ')&&(alp.charAt(i+1)!=','||alp.charAt(i+1)!=' '))
                {
                    if(alp.charAt(i)=='.'&&alp.charAt(i+2)=='.')
                    {
                        return false;
                    }
                    if(alp.charAt(i)=='.'&&alp.charAt(i+1)=='.')
                    {
                        return false;
                    }
                    if(alp.charAt(i)!='.'&&alp.charAt(i+2)!='.')
                    {
                        if((alp.charAt(i)>'0'||alp.charAt(i)<'9')&&((alp.charAt(i+1)<'0'||alp.charAt(i+1)>'9')&&alp.charAt(i+1)!='.')&&(alp.charAt(i+2)>'0'&&alp.charAt(i+2)<'9'))
                        {
                            return false;
                        }
                        if(((alp.charAt(i)<'0'||alp.charAt(i)>'9')&&alp.charAt(i)!='.')&&((alp.charAt(i+1)>'0'&&alp.charAt(i+1)<'9'))&&((alp.charAt(i+2)<'0'||alp.charAt(i+2)>'9')&&alp.charAt(i+1)!='.'))
                        {
                            return false;
                        }
                    }
                    else if(alp.charAt(i)=='.'&&alp.charAt(i+2)!='.')
                    {
                        if((alp.charAt(i+2)<'0'||alp.charAt(i+2)>'9'))
                        {
                            return false;
                        }
                    }
                }
            }
            if(i==length-2)
            {
                break;
            }
        }
        return true;
    }
    
    public static boolean JudgmentRepetition(int choose) {
        if(choose==1)
        {
            if(x1==x2&&y1==y2)
            {
                return false;
            }
        }
        return true;
    }
        
    public static boolean WholeCheckInputIegitimate(String alp,int nums) {
        int length = alp.length();
        int count = 0;
        for(int i = 0;i < length;i++)
        {
            if(alp.charAt(i)==',')
                count++;
        }
        if(count!=nums)
        {
            return false;
        }
        return true;
    }
    
    public static double CharacterTransformation(String transfer) {
        double nums=(double) Double.parseDouble(transfer);
        return nums;
    }
    
    public static void DigitalConversion(double x,boolean flag1) {
        String str = String.valueOf(x);
        String[] arr = str.split("\\.");
        if(arr[1].length()>6)
        {
            if(str.charAt(7)=='0'&&str.charAt(8)<'5')
            {
                System.out.print((float)x);
            }
            else
            {
                System.out.printf("%.6f",x);
            }
        }
        else
        {
            System.out.print(x);
        }
        if(flag1==true)
            System.out.print(" ");
    }
    
    public static void TriangleAngle(double a,double b,double c) {
        if (Math.abs(c*c-(a*a+b*b))<0.000001||Math.abs(b*b-(a*a+c*c))<0.000001||Math.abs(a*a-(b*b+c*c))<0.000001)
        {
            System.out.println("false true false");
        }
        else if(a * a > b * b + c * c || b * b > a * a + c * c || c * c > a * a + b * b)
        {
            System.out.println("true false false");
        }
        else
        {
            System.out.println("false false true");
        }
    }
    
    private static void Calculation1(String alp,String falp) {
        int length = alp.length();
        if(!WholeCheckInputIegitimate(alp,3))
        {
            System.out.println("wrong number of points");
            System.exit(0);
        }
        String X1 = alp.substring(0,alp.indexOf(','));
        alp = alp.substring(alp.indexOf(',')+1,length);
        length = alp.length();
        String Y1 = alp.substring(0,alp.indexOf(' '));
        alp = alp.substring(alp.indexOf(' ')+1,length);
        length = alp.length();
        String X2 = alp.substring(0,alp.indexOf(','));
        alp = alp.substring(alp.indexOf(',')+1,length);
        length = alp.length();
        String Y2 = alp.substring(0,alp.indexOf(' '));
        alp = alp.substring(alp.indexOf(' ')+1,length);
        length = alp.length();
        String X3 = alp.substring(0,alp.indexOf(','));
        alp = alp.substring(alp.indexOf(',')+1,length);
        length = alp.length();
        String Y3 = alp.substring(0,length);
        x1 = CharacterTransformation(X1);
        y1 = CharacterTransformation(Y1);
        x2 = CharacterTransformation(X2);
        y2 = CharacterTransformation(Y2);
        x3 = CharacterTransformation(X3);
        y3 = CharacterTransformation(Y3);
        if(!JudgmentRepetition(2))
        {
            System.out.println("points coincide");
            System.exit(0);
        }
        double a = Math.sqrt(Math.pow(x1-x2,2)+Math.pow(y1-y2,2));
        double b = Math.sqrt(Math.pow(x2-x3,2)+Math.pow(y2-y3,2));
        double c = Math.sqrt(Math.pow(x1-x3,2)+Math.pow(y1-y3,2));
        if(!TriangleJudgment(a,b,c))
        {
            System.out.println("data error");
            System.exit(0);
        }
        if(falp.charAt(0)=='1')
        {
            if((a==b)||(a==c)||(b==c))
            {
                System.out.print("true ");
            }
            else
            {
                System.out.print("false ");
            }
            if(a==b&&b==c)
            {
                System.out.print("true");
            }
            else
            {
                System.out.print("false");
            }
        }
        if(falp.charAt(0)=='2')
        {
            double C =(a+b+c);
            double S =area(a,b,c);
            double x =((x1+x2+x3)/3.0);
            DigitalConversion(C,true);
            DigitalConversion(S,true);
            DigitalConversion(x,false);
            System.out.print(",");
            double y = ((y1+y2+y3)/3.0);
            DigitalConversion(y,false);
        }
        if(falp.charAt(0)=='3')
        {
            TriangleAngle(a,b,c);
        }
    }
    
    public static double max(double a,double b) {
        if(a>b)
            return a;
        return b;
    }
    
    public static double min(double a,double b) {
        if(a<b)
            return a;
        return b;
    }
    
    public static boolean TriangleJudgment(double a,double b,double c) {
        if((a+b>c && a-b<c) && (a+c>b && a-c<b) && (b+c>a && b-c<a))
        {
            return true;
        }
        return false;
    }
    
    public static double area(double a,double b,double c) {
        double C = a+b+c;
        return Math.sqrt((C/2)*(C/2-a)*(C/2-b)*(C/2-c));
    }
    
    public static int IntersectionJudgment()//交点个数
    {
        boolean flag1 = false;
        boolean flag2 = false;
        boolean flag3 = false;
        if((x1-x2)!=0)
        {
            if((y3==(y2+(x3-x2)*(y2-y1)/(x2-x1))&&y4==(y2+(x4-x2)*(y2-y1)/(x2-x1)))||(y3==(y2+(x3-x2)*(y2-y1)/(x2-x1))&&y5==(y2+(x5-x2)*(y2-y1)/(x2-x1)))||(y4==(y2+(x4-x2)*(y2-y1)/(x2-x1))&&y5==(y2+(x5-x2)*(y2-y1)/(x2-x1))))
            {
                return -1;
            }
            if(y3>(y2+(x3-x2)*(y2-y1)/(x2-x1)))
                flag1=true;
            else
                flag1=false;
            if(y4>(y2+(x4-x2)*(y2-y1)/(x2-x1)))
                flag2=true;
            else
                flag2=false;
            if(y5>(y2+(x5-x2)*(y2-y1)/(x2-x1)))
                flag3=true;
            else
                flag3=false;
        }
        else
        {
            if((x3==x1&&x4==x1)||(x3==x1&&x5==x1)||(x4==x1&&x5==x1))
            {
                return -1;
            }
            if(x3==x1||x4==x1||x5==x1)
            {
                return 1;
            }
            if(x3>x1)
                flag1=true;
            else
                flag1=false;
            if(x4>x1)
                flag2=true;
            else
                flag2=false;
            if(x5>x1)
                flag3=true;
            else
                flag3=false;
        }
        if((flag1==true&&flag2==true&&flag3==false)||(flag1==false&&flag2==false&&flag3==true))
        {
            center1=x5;center2=y5;same1=x3;same2=y3;same3=x4;same4=y4;
            return 2;
        }
        else if((flag1==false&&flag2==true&&flag3==false)||(flag1==true&&flag2==false&&flag3==true))
        {
            center1=x4;center2=y4;same1=x3;same2=y3;same3=x5;same4=y5;
            return 2;
        }
        else if((flag1==false&&flag2==true&&flag3==true)||(flag1==true&&flag2==false&&flag3==false))
        {
            center1=x3;center2=y3;same1=x4;same2=y4;same3=x5;same4=y5;
            return 2;
        }
        else if(y3==(y2+(x3-x2)*(y2-y1)/(x2-x1))||y4==(y2+(x4-x2)*(y2-y1)/(x2-x1))||y5==(y2+(x5-x2)*(y2-y1)/(x2-x1)))
        {
            return 1;
        }
            return 0;
    }
    
    public static void Calculation2(String alp) {
        int length = alp.length();
        if(!WholeCheckInputIegitimate(alp,5))
        {
            System.out.println("wrong number of points");
            System.exit(0);
        }
        String X1 = alp.substring(0,alp.indexOf(','));
        alp = alp.substring(alp.indexOf(',')+1,length);
        length = alp.length();
        String Y1 = alp.substring(0,alp.indexOf(' '));
        alp = alp.substring(alp.indexOf(' ')+1,length);
        length = alp.length();
        String X2 = alp.substring(0,alp.indexOf(','));
        alp = alp.substring(alp.indexOf(',')+1,length);
        length = alp.length();
        String Y2 = alp.substring(0,alp.indexOf(' '));
        alp = alp.substring(alp.indexOf(' ')+1,length);
        length = alp.length();
        String X3 = alp.substring(0,alp.indexOf(','));
        alp = alp.substring(alp.indexOf(',')+1,length);
        length = alp.length();
        String Y3 = alp.substring(0,alp.indexOf(' '));
        alp = alp.substring(alp.indexOf(' ')+1,length);
        length = alp.length();
        String X4 = alp.substring(0,alp.indexOf(','));
        alp = alp.substring(alp.indexOf(',')+1,length);
        length = alp.length();
        String Y4 = alp.substring(0,alp.indexOf(' '));
        alp = alp.substring(alp.indexOf(' ')+1,length);
        length = alp.length();
        String X5 = alp.substring(0,alp.indexOf(','));
        alp = alp.substring(alp.indexOf(',')+1,length);
        length = alp.length();
        String Y5 = alp.substring(0,length);
        x1 = CharacterTransformation(X1);
        y1 = CharacterTransformation(Y1);
        x2 = CharacterTransformation(X2);
        y2 = CharacterTransformation(Y2);
        x3 = CharacterTransformation(X3);
        y3 = CharacterTransformation(Y3);
        x4 = CharacterTransformation(X4);
        y4 = CharacterTransformation(Y4);
        x5 = CharacterTransformation(X5);
        y5 = CharacterTransformation(Y5);
        double a = Math.sqrt(Math.pow(x3-x4,2)+Math.pow(y3-y4,2));
        double b = Math.sqrt(Math.pow(x3-x5,2)+Math.pow(y3-y5,2));
        double c = Math.sqrt(Math.pow(x4-x5,2)+Math.pow(y4-y5,2));
        if(!JudgmentRepetition(1))
        {
            System.out.println("points coincide");
            System.exit(0);
        }
        if(!TriangleJudgment(a,b,c))
        {
            System.out.println("data error");
            System.exit(0);
        }
        if(IntersectionJudgment()==2)
        {
            double n1=0,n2=0,n3=0;
            double m1=0,m2=0,m3=0,m4=0;
            double S1=0,S2=0;
            if((x2-x1)!=0&&(same1-center1)!=0&&(same3-center1)!=0)
            {
                double a1=(y2-y1)/(x2-x1);
                double b1=-1;
                double c1=y1-((y2-y1)*x1/(x2-x1));
                double a2=(same2-center2)/(same1-center1);
                double b2=-1;
                double c2=center2-((same2-center2)*center1/(same1-center1));
                double a3=(same4-center2)/(same3-center1);
                double b3=-1;
                double c3=same4-((same4-center2)*same3/(same3-center1));
                 m2 = (c1 * a2 - c2 * a1) / (a1 * b2 - a2 * b1);
                 m1 = (c2 * b1 - c1 * b2) / (a1 * b2 - a2 * b1);
                 m4 = (c1 * a3 - c3 * a1) / (a1 * b3 - a3 * b1);
                 m3 = (c3 * b1 - c1 * b3) / (a1 * b3 - a3 * b1);
                n1=Math.sqrt(Math.pow(center1-m3, 2)+Math.pow(center2-m4, 2));
                n2=Math.sqrt(Math.pow(center1-m1, 2)+Math.pow(center2-m2, 2));
                n3=Math.sqrt(Math.pow(m3-m1, 2)+Math.pow(m4-m2, 2));
            }
            else if((x2-x1)==0&&(same1-center1)!=0&&(same3-center1)!=0)
            {
                double yy1=center2+((center2-same2)*(x1-center1)/(center1-same1));
                double yy2=center2+((center2-same4)*(x1-center1)/(center1-same3));
                n1=Math.sqrt(Math.pow(center1-x1, 2)+Math.pow(center2-yy1, 2));
                n2=Math.sqrt(Math.pow(center1-x1, 2)+Math.pow(center2-yy2, 2));
                n3=yy1-yy2;
            }
            else if((x2-x1)!=0&&(same1-center1)==0&&(same3-center1)!=0)
            {
                double a1=(y2-y1)/(x2-x1);
                double b1=-1;
                double c1=y1-((y2-y1)*x1/(x2-x1));
                double a3=(same4-center2)/(same3-center1);
                double b3=-1;
                double c3=same4-((same4-center2)*same3/(same3-center1));
                m4 = (c1 * a3 - c3 * a1) / (a1 * b3 - a3 * b1);
                m3 = (c3 * b1 - c1 * b3) / (a1 * b3 - a3 * b1);
                n1=Math.sqrt(Math.pow(center1-m3, 2)+Math.pow(center2-m4, 2));
                n3=y1+(y2-y1)*(same1-x1)/(x2-x1)-center2;
                n2=Math.sqrt(Math.pow(m3-same1, 2)+Math.pow(m4-(n3+center2), 2));
            }
            else if((x2-x1)!=0&&(same1-center1)!=0&&(same3-center1)==0)
            {
                double a1=(y2-y1)/(x2-x1);
                double b1=-1;
                double c1=y1-((y2-y1)*x1/(x2-x1));
                double a2=(same2-center2)/(same1-center1);
                double b2=-1;
                double c2=center2-((same2-center2)*center1/(same1-center1));
                m2 = (c1 * a2 - c2 * a1) / (a1 * b2 - a2 * b1);
                m1 = (c2 * b1 - c1 * b2) / (a1 * b2 - a2 * b1);
                n2=Math.sqrt(Math.pow(center1-m1, 2)+Math.pow(center2-m2, 2));
                n3=y1+(y2-y1)*(same3-x1)/(x2-x1)-center2;
                n1=Math.sqrt(Math.pow(m1-same3, 2)+Math.pow(m2-(n3+center2), 2));
            }
            S1=area(n1,n2,n3);
            S2=area(a,b,c)-S1;
            System.out.print("2 ");
            if(S1>S2)
            {
                DigitalConversion(S2,true);
                DigitalConversion(S1,false);
            }
            else
            {
                DigitalConversion(S1,true);
                DigitalConversion(S2,false);
            }
        }
        if(IntersectionJudgment()==1)
        {
            System.out.println("1");
        }
        if(IntersectionJudgment()==0)
        {
            System.out.println("0");
        }
        if(IntersectionJudgment()==-1)
        {
            System.out.println("The point is on the edge of the triangle");
        }
    }
    
    public static void Calculation3(String alp) {
        int length = alp.length();
        if(!WholeCheckInputIegitimate(alp,4))
        {
            System.out.println("wrong number of points");
            System.exit(0);
        }
        String X1 = alp.substring(0,alp.indexOf(','));
        alp = alp.substring(alp.indexOf(',')+1,length);
        length = alp.length();
        String Y1 = alp.substring(0,alp.indexOf(' '));
        alp = alp.substring(alp.indexOf(' ')+1,length);
        length = alp.length();
        String X2 = alp.substring(0,alp.indexOf(','));
        alp = alp.substring(alp.indexOf(',')+1,length);
        length = alp.length();
        String Y2 = alp.substring(0,alp.indexOf(' '));
        alp = alp.substring(alp.indexOf(' ')+1,length);
        length = alp.length();
        String X3 = alp.substring(0,alp.indexOf(','));
        alp = alp.substring(alp.indexOf(',')+1,length);
        length = alp.length();
        String Y3 = alp.substring(0,alp.indexOf(' '));
        alp = alp.substring(alp.indexOf(' ')+1,length);
        length = alp.length();
        String X4 = alp.substring(0,alp.indexOf(','));
        alp = alp.substring(alp.indexOf(',')+1,length);
        length = alp.length();
        String Y4 = alp.substring(0,length);
        x1 = CharacterTransformation(X1);
        y1 = CharacterTransformation(Y1);
        x2 = CharacterTransformation(X2);
        y2 = CharacterTransformation(Y2);
        x3 = CharacterTransformation(X3);
        y3 = CharacterTransformation(Y3);
        x4 = CharacterTransformation(X4);
        y4 = CharacterTransformation(Y4);
        double a = Math.sqrt(Math.pow(x3-x4,2)+Math.pow(y3-y4,2));
        double b = Math.sqrt(Math.pow(x3-x5,2)+Math.pow(y3-y5,2));
        double c = Math.sqrt(Math.pow(x4-x5,2)+Math.pow(y4-y5,2));
        if(!TriangleJudgment(a,b,c))
        {
            System.out.println("data error");
            System.exit(0);
        }
        double aa = (x1-x2)*(y1-y3)-(y1-y2)*(x1-x3);
        double bb = (x1-x3)*(y1-y4)-(y1-y3)*(x1-x4);
        double cc = (x1-x4)*(y1-y2)-(y1-y4)*(x1-x2);
        if((aa < 0 && bb < 0 && cc < 0)||(aa > 0 && bb > 0 && cc > 0))  
        {
            System.out.println("in the triangle");
        }
        else if(aa==0||bb==0||cc==0)
        {
            if(aa==0)
            {
                if(x1>=min(x2,x3)&&x1<=max(x2,x3)&&y1>=min(x2,x3)&&y1<=max(x2,x3))
                {
                    System.out.println("on the triangle");
                }
                else
                {
                    System.out.println("outof the triangle");
                }
            }
            else if(bb==0)
            {
                if(x1>=min(x4,x3)&&x1<=max(x4,x3)&&y1>=min(x4,x3)&&y1<=max(x4,x3))
                {
                    System.out.println("on the triangle");
                }
                else
                {
                    System.out.println("outof the triangle");
                }
            }
            else if(cc==0)
            {
                if(x1>=min(x4,x2)&&x1<=max(x4,x2)&&y1>=min(x4,x2)&&y1<=max(x4,x2))
                {
                    System.out.println("on the triangle");
                }
                else
                {
                    System.out.println("outof the triangle");
                }
            }
        }
        else
        {
            System.out.println("outof the triangle");
        }
    }
    
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        String falp = input.nextLine();
        if((falp.charAt(0)>'5'||falp.charAt(0)<'1')||(falp.charAt(1)!=':'))
        {
            System.out.println("Wrong Format");
            System.exit(0);
        }
        int length = falp.length();
        String alp = falp.substring(2,length);
        if(!LocalCheckInputIegitimate(alp))
        {
            System.out.println("Wrong Format");
            System.exit(0);
        }
        if(falp.charAt(0)=='1'||falp.charAt(0)=='2'||falp.charAt(0)=='3') 
        {
            Calculation1(alp,falp);
        }
        if(falp.charAt(0)=='4')
        {
            Calculation2(alp);
        }
        if(falp.charAt(0)=='5')
        {
            Calculation3(alp);
        }
    }
}

采坑心得：

（1）关于直角三角形的判断不能直接用a²+b²=c²的这么一种形式，应为a,b,c均为double型，Java在计算时存在精度的丢失，即为所说的误差，正确的表示方法应当为

这么一种形式

 

（2）判断点的数量可以采取数逗号的方法，逗号有几个那就是几个点，前提是要保证输入的数据是合法的

（3）判断数据的合法性应当考虑各种情况。

改进建议：

（1）从整体看，程序的整个过程都是在main里进行的，这样就显得程序很繁琐且没有条理，main中的耦合性太强，应该设计点类和线类，相关的方法放在点类和线类中。

（2）对数据合法性的判断过于繁琐，这里采用的是最基本的for循环逐一判断，这样的效率非常的低，而且需要写的代码很多，使得代码繁琐，应当使用正则表达式来判断数据合法性的问题

（3）数据的提取过于繁琐，应当采用数组的形式，结合正则表达式的提取将相应的数据存放置数组中。

---

 

题目集04—7-2：7-2 点线形系列4-凸四边形的计算

源码设计及解释：

  这次同样是图形类设计的题目，但采取的是不同的设计思路和方法，首先设计两个类，即点类和线类

点类：                                                                               线类：        

          

 

 

对于数据合法性的判断采用的是正则表达式：

 

 

 

 

 数据的提取使用数组和正则提取的结合：

 

 

源码：

 

 

import java.util.HashSet;
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {
    static Point A;
    static Point B;
    static Point C;
    static Point D;
    static Point u1;
    static Point u2;
    static HashSet<Point> sites = new HashSet<Point>();
    
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String alp = in.nextLine();
        if(!CheckInputIegitimate(alp)) {
            System.out.println("Wrong Format");
            System.exit(0);
        }
        double[] array = new double[20];
        Pattern pattern = Pattern.compile("(-?\\d*)\\.?\\d+");
        Matcher matcher = pattern.matcher(alp.substring(2, alp.length()));
        int count = 0;
        while(matcher.find()) {
            array[count] = Double.parseDouble(matcher.group(0));
            count++;
        }
        if(alp.charAt(0)=='1'||alp.charAt(0)=='2'||alp.charAt(0)=='3') {
            A = new Point(array[0],array[1]);
            B = new Point(array[2],array[3]);
            C = new Point(array[4],array[5]);
            D = new Point(array[6],array[7]);
            if(alp.charAt(0)=='1') {
                operate1(alp.substring(2, alp.length()));
            }
            if(alp.charAt(0)=='2') {
                operate2(alp.substring(2, alp.length()));
            }
            if(alp.charAt(0)=='3') {
                operate3(alp.substring(2, alp.length()));
            }
        }
        if(alp.charAt(0)=='4') {
            A = new Point(array[4],array[5]);
            B = new Point(array[6],array[7]);
            C = new Point(array[8],array[9]);
            D = new Point(array[10],array[11]);
            u1 = new Point(array[0],array[1]);
            u2 = new Point(array[2],array[3]);
            operate4(alp.substring(2, alp.length()));
        }
        if(alp.charAt(0)=='5') {
            u1 = new Point(array[0],array[1]);
            A = new Point(array[2],array[3]);
            B = new Point(array[4],array[5]);
            C = new Point(array[6],array[7]);
            D = new Point(array[8],array[9]);
            operate5(alp.substring(2, alp.length()));
        }
    }

    public static void operate1(String alp) {//选项1操作
        dataDetection(alp,4);
        if(JudgeQuadrilateral()) {
            System.out.println("false false");
            System.exit(0);
        }
        Line l1 = new Line(A,B);Line l2 = new Line(A,C);Line l3 = new Line(A,D);Line l4 = new Line(B,C);Line l5 = new Line(B,D);Line l6 = new Line(C,D);
        if(l1.newLineSegment(C)||l1.newLineSegment(D)||l2.newLineSegment(B)||l2.newLineSegment(D)||l3.newLineSegment(B)||l3.newLineSegment(C)||l4.newLineSegment(A)||l4.newLineSegment(D)||l5.newLineSegment(A)||l5.newLineSegment(C)||l6.newLineSegment(A)||l6.newLineSegment(B)) {            
            System.out.println("false false");
        }else {//这里一定能构成四边形
            System.out.print("true ");
            if(A.getSlope(B)==C.getSlope(D)&&A.CalculateDistance(B)==C.CalculateDistance(D)) {
                System.out.print("true");
            }else {
                System.out.print("false");
            }
        }
    }
    
    public static void operate2(String alp) {//选项2操作
        boolean flag1 = false;
        boolean flag2 = false;
        if(!NumberCheckInputIegitimate(alp,4)) {
            System.out.println("wrong number of points");
            System.exit(0);
        }
        if(JudgeQuadrilateral()) {
            System.out.println("not a quadrilateral");
            System.exit(0);
        }
        Line l1 = new Line(A,B);Line l2 = new Line(A,C);Line l3 = new Line(A,D);Line l4 = new Line(B,C);Line l5 = new Line(B,D);Line l6 = new Line(C,D);
        if(l1.newLineSegment(C)||l1.newLineSegment(D)||l2.newLineSegment(B)||l2.newLineSegment(D)||l3.newLineSegment(B)||l3.newLineSegment(C)||l4.newLineSegment(A)||l4.newLineSegment(D)||l5.newLineSegment(A)||l5.newLineSegment(C)||l6.newLineSegment(A)||l6.newLineSegment(B)) {
            System.out.println("not a quadrilateral");
            System.exit(0);
        }    
        if(A.getSlope(B)==C.getSlope(D)&&A.CalculateDistance(B)==C.CalculateDistance(D)) {//平行四边形
            if(A.CalculateDistance(B)==A.CalculateDistance(D)) {//邻边相等为菱形
                flag1 = true;
                System.out.print("true ");
            }else {
                System.out.print("false ");
            }
            if(Math.abs(Math.pow(B.CalculateDistance(D),2)-Math.pow(A.CalculateDistance(B),2)-Math.pow(A.CalculateDistance(D),2))<1e-6) {//有一直角为矩形
                flag2 = true;
                System.out.print("true ");
            }else {
                System.out.print("false ");
            }
            if(flag1==true&&flag2==true) {
                System.out.print("true");
            }else {
                System.out.print("false");
            }
        }else {
            System.out.print("false false false");
        }
    }
    
    public static void operate3(String alp) {//选项3操作
        dataDetection(alp,4);
        if((A.getSlope(B)==A.getSlope(C))||(B.getSlope(C)==B.getSlope(D))||(A.getSlope(C)==A.getSlope(D))||(A.getSlope(B)==B.getSlope(D))) {
            System.out.println("not a quadrilateral");
            System.exit(0);
        }    //前提条件，一定能构成四边形
        if(pointInsideTriangle(A,B,C,D)||pointInsideTriangle(B,A,C,D)||pointInsideTriangle(C,A,B,D)||pointInsideTriangle(D,A,B,C)) {
            System.out.print("false ");
        }else {
            System.out.print("true ");
        }
        DigitalConversion(A.CalculateDistance(B)+B.CalculateDistance(C)+C.CalculateDistance(D)+D.CalculateDistance(A),true);
        Line l1 = new Line(A,C);
        Line l2 = new Line(B,D);
        DigitalConversion(0.5*A.CalculateDistance(C)*B.CalculateDistance(D)*(l1.GetIncludedAngle(l2)),false);
    }
    
    public static void operate4(String alp) {
        if(!NumberCheckInputIegitimate(alp,6)) {
            System.out.println("wrong number of points");
            System.exit(0);
        }
        if(u1.CoincidenceJudgment(u2)) {
            System.out.println("points coincide");
            System.exit(0);
        }
        Line l = new Line(u1,u2);
        Line l1 = new Line(A,B);Line l2 = new Line(B,C);Line l3 = new Line(C,D); Line l4 = new Line(D,A);Line l5 = new Line(A,C); Line l6 = new Line(B,D);
        if(l1.newLineSegment(C)||l1.newLineSegment(D)||l2.newLineSegment(A)||l2.newLineSegment(D)||l3.newLineSegment(B)||l3.newLineSegment(A)||l4.newLineSegment(B)||l4.newLineSegment(C)||l5.newLineSegment(B)||l5.newLineSegment(D)||l6.newLineSegment(A)||l6.newLineSegment(C)) {
            if(l5.newLineSegment(D)) {//D在CA上，D是重复点
                Caculate(l,A,B,C);
            }
            else if(l5.newLineSegment(B)) {
                Caculate(l,A,D,C);
            }
            else if(l6.newLineSegment(C)) {
                Caculate(l,A,B,D);
            }
            else if(l6.newLineSegment(A)) {
                if(l.getSlope()==0)
                Caculate(l,C,B,D);
            }else if(A.CoincidenceJudgment(C)) {
                Caculate(l,A,B,D);
            }else if(A.CoincidenceJudgment(B)) {
                Caculate(l,A,C,D);
            }else if(A.CoincidenceJudgment(D)) {
                Caculate(l,C,B,A);
            }else if(B.CoincidenceJudgment(C)) {
                Caculate(l,A,B,D);
            }else if(B.CoincidenceJudgment(D)) {
                Caculate(l,C,B,A);
            }else if(C.CoincidenceJudgment(D)) {
                Caculate(l,A,B,D);
            }else {
                System.out.println("not a quadrilateral or triangle");
            }
        }else {//多边形
            int intersection = 0;
           if(JudgeQuadrilateral()) {
            System.out.println("not a quadrilateral or triangle");
            System.exit(0);
            }
            if(l.StraightLine(A)&&l.StraightLine(B)||l.StraightLine(A)&&l.StraightLine(D)||l.StraightLine(B)&&l.StraightLine(C)||l.StraightLine(C)&&l.StraightLine(D)) {
                System.out.println("The line is coincide with one of the lines");
                System.exit(0);
            }
            intersection = GetIntersection(l,l1,l2,l3,l4);
            if(intersection==2) {
                if(pointInsideTriangle(A,B,C,D)||pointInsideTriangle(B,A,C,D)||pointInsideTriangle(C,A,B,D)||pointInsideTriangle(D,A,B,C)){
                    ConcaveQuadrilateral(l,l1,l2,l3,l4);
                }else {
                    ConvexQuadrilateral(l,l1,l2,l3,l4);
                }
            }else {
                System.out.println(intersection);
            }
        }    
    }
    
    public static void operate5(String alp) {
        int choose = 0;
        if(JudgeQuadrilateral()) {
            System.out.println("not a quadrilateral or triangle");
            System.exit(0);
        }
        Line l1 = new Line(A,B);Line l2 = new Line(B,C);Line l3 = new Line(C,D); Line l4 = new Line(D,A);Line l5 = new Line(A,C); Line l6 = new Line(B,D);
        if(l1.newLineSegment(C)||l1.newLineSegment(D)||l2.newLineSegment(A)||l2.newLineSegment(D)||l3.newLineSegment(B)||l3.newLineSegment(A)||l4.newLineSegment(B)||l4.newLineSegment(C)||l5.newLineSegment(B)||l5.newLineSegment(D)||l6.newLineSegment(A)||l6.newLineSegment(C)) {
            if(l5.newLineSegment(D)) {//D在CA上，D是重复点
                choose = PointInTriangle(u1,A,B,C);
            }
            else if(l5.newLineSegment(B)) {
                choose = PointInTriangle(u1,A,D,C);
            }
            else if(l6.newLineSegment(C)) {
                choose = PointInTriangle(u1,A,B,D);
            }
            else if(l6.newLineSegment(A)) {
                choose = PointInTriangle(u1,C,B,D);
            }else {
                System.out.println("not a quadrilateral or triangle");
            }
            if(choose==0) {
                System.out.println("outof the triangle");
            }else if(choose==1) {
                System.out.println("in the triangle");
            }else {
                System.out.println("on the triangle");
            }
        }else {//多边形
            int flag1 = 0;int flag2=0;
            flag1=PointInTriangle(u1,A,C,D);
            flag2=PointInTriangle(u1,A,B,C);
            if(flag1==1||flag2==1||(l5.newLineSegment(u1)&&!u1.CoincidenceJudgment(A)&&!u1.CoincidenceJudgment(C))) {
                choose = 1;
            }else if(flag1==2||flag2==2) {
                choose = 2;
            }else {
                choose = 0;
            }
            if(choose==0) {
                System.out.println("outof the quadrilateral");
            }else if(choose==1) {
                System.out.println("in the quadrilateral");
            }else {
                System.out.println("on the quadrilateral");
            }
        }
    }
    
    public static int PointInTriangle(Point p1,Point p2,Point p3,Point p4) {
        double flag1 = (p1.getX()-p2.getX())*(p1.getY()-p3.getY())-(p1.getY()-p2.getY())*(p1.getX()-p3.getX());
        double flag2 = (p1.getX()-p3.getX())*(p1.getY()-p4.getY())-(p1.getY()-p3.getY())*(p1.getX()-p4.getX());
        double flag3 = (p1.getX()-p4.getX())*(p1.getY()-p2.getY())-(p1.getY()-p4.getY())*(p1.getX()-p2.getX());
        if((flag1<0&&flag2<0&&flag3<0)||(flag1>0&&flag2>0&&flag3>0)) {
            return 1;
        }else if(flag1==0||flag2==0||flag3==0) {
            if(flag1==0) {
                if(new Line(p2,p3).newLineSegment(p1)){
                    return 2;
                }else {
                    return 0;
                }
            }else if(flag2==0) {
                if(new Line(p3,p4).newLineSegment(p1)) {
                    return 2;
                }else {
                    return 0;
                }
            }else if(flag3==0) {
                if(new Line(p2,p4).newLineSegment(p1)) {
                    return 2;
                }else {
                    return 0;
                }
            }
        }
        return 0;
    }
    
    public static void ConcaveQuadrilateral(Line l,Line l1,Line l2,Line l3,Line l4) {
        double S = 0.5*A.CalculateDistance(C)*B.CalculateDistance(D)*new Line(A,C).GetIncludedAngle(new Line(B,D));
        double s1 = 0;
        double s2 = 0;
        Point n1 = l.GetPoint(l1);Point n2 = l.GetPoint(l2);Point n3 = l.GetPoint(l3);Point n4 = l.GetPoint(l4);
        if(l.StraightLine(A)&&l.StraightLine(C)) {
            s1 = area(A.CalculateDistance(B),A.CalculateDistance(C),B.CalculateDistance(C));
            s2 = S-s1;
            input(s1,s2);
            System.exit(0);
        }
        if(l.StraightLine(B)&&l.StraightLine(D)) {
            s1 = area(A.CalculateDistance(B),A.CalculateDistance(D),B.CalculateDistance(D));
            s2 = S-s1;
            input(s1,s2);
            System.exit(0);
        }
        if(pointInsideTriangle(D,A,B,C)&&l.StraightLine(C)&&l1.LineSegment(n1)) {
            s1 = area(B.CalculateDistance(C),C.CalculateDistance(n1),B.CalculateDistance(n1));
            s2 = S-s1;
            input(s1,s2);
            System.exit(0);
        }
        if(n1!=null&&n2!=null) {
            if(l1.LineSegment(n1)&&l2.LineSegment(n2)) {
                s1 = area(n1.CalculateDistance(n2),n1.CalculateDistance(B),n2.CalculateDistance(B));
                s2 = S - s1;
            }
        }
        if(n1!=null&&n3!=null) {
            if(l1.LineSegment(n1)&&l3.LineSegment(n3)) {
                if(pointInsideTriangle(A,B,C,D)||pointInsideTriangle(C,A,B,D)) {
                    s1 = area(C.CalculateDistance(n1),B.CalculateDistance(n1),C.CalculateDistance(B))+area(C.CalculateDistance(n1),C.CalculateDistance(n3),n1.CalculateDistance(n3));
                    s2 = S-s1;
                }else {
                    s1 = area(C.CalculateDistance(B),C.CalculateDistance(n3),B.CalculateDistance(n3))+area(B.CalculateDistance(n1),B.CalculateDistance(n3),n1.CalculateDistance(n3));
                    s2 = S- s1;
                }
            }
        }
        if(n1!=null&&n4!=null) {
            if(l1.LineSegment(n1)&&l4.LineSegment(n4)) {
                s1 = area(A.CalculateDistance(n1),A.CalculateDistance(n4),n1.CalculateDistance(n4));
                s2 = S - s1;
            }
        }
        if(n2!=null&&n3!=null) {
            if(l2.LineSegment(n2)&&l3.LineSegment(n3)) {
                s1 = area(n2.CalculateDistance(n3),n2.CalculateDistance(C),n3.CalculateDistance(C));
                s2 = S - s1;
            }
        }
        if(n2!=null&&n4!=null) {
            if(l2.LineSegment(n2)&&l4.LineSegment(n4)) {
                if(pointInsideTriangle(A,B,C,D)||pointInsideTriangle(C,A,B,D)) {
                    s1 = area(A.CalculateDistance(n2),A.CalculateDistance(n4),n2.CalculateDistance(n4))+area(A.CalculateDistance(n2),n2.CalculateDistance(B),A.CalculateDistance(B));
                    s2 = S-s1;
                }else {
                    s1 = area(B.CalculateDistance(n2),B.CalculateDistance(n4),n2.CalculateDistance(n4))+area(B.CalculateDistance(n4),A.CalculateDistance(n4),A.CalculateDistance(B));
                    s2 = S - s1;
                }
            }
        }
        if(n3!=null&&n4!=null) {
            if(l3.LineSegment(n3)&&l4.LineSegment(n4)) {
                s1 = area(D.CalculateDistance(n4),D.CalculateDistance(n3),n4.CalculateDistance(n3));
                s2 = S - s1;
            }
        }
        input(s1,s2);
    }
    
    public static void ConvexQuadrilateral(Line l,Line l1,Line l2,Line l3,Line l4) {//凸四边形
        double S = 0.5*A.CalculateDistance(C)*B.CalculateDistance(D)*new Line(A,C).GetIncludedAngle(new Line(B,D));
        double s1 = 0;
        double s2 = 0;
        Point n1 = l.GetPoint(l1);Point n2 = l.GetPoint(l2);Point n3 = l.GetPoint(l3);Point n4 = l.GetPoint(l4);
        if(l.StraightLine(B)&&l.StraightLine(D)) {
            s1 = area(A.CalculateDistance(B),A.CalculateDistance(D),B.CalculateDistance(D));
            s2 = S-s1;
            input(s1,s2);
            System.exit(0);
        }
        if(l.StraightLine(A)&&l.StraightLine(C)) {
            s1 = area(A.CalculateDistance(B),A.CalculateDistance(C),B.CalculateDistance(C));
            s2 = S-s1;
            input(s1,s2);
            System.exit(0);
        }
        if(n1!=null&&n2!=null) {
            if(l1.LineSegment(n1)&&l2.LineSegment(n2)) {
                s1 = area(n1.CalculateDistance(n2),n1.CalculateDistance(B),n2.CalculateDistance(B));
                s2 = S - s1;
            }
        }
        if(n1!=null&&n3!=null) {
            if(l1.LineSegment(n1)&&l3.LineSegment(n3)) {
                s1 = area(A.CalculateDistance(n1),A.CalculateDistance(n3),n1.CalculateDistance(n3))+area(A.CalculateDistance(n3),D.CalculateDistance(n3),A.CalculateDistance(D));
                s2 = S-s1;
            }
        }
        if(n1!=null&&n4!=null) {
            if(l1.LineSegment(n1)&&l4.LineSegment(n4)) {
                s1 = area(A.CalculateDistance(n1),A.CalculateDistance(n4),n1.CalculateDistance(n4));
                s2 = S - s1;
            }
        }
        if(n2!=null&&n3!=null) {
            if(l2.LineSegment(n2)&&l3.LineSegment(n3)) {
                s1 = area(n2.CalculateDistance(n3),n2.CalculateDistance(C),n3.CalculateDistance(C));
                s2 = S - s1;
            }
        }
        if(n2!=null&&n4!=null) {
            if(l2.LineSegment(n2)&&l4.LineSegment(n4)) {
                s1 = area(A.CalculateDistance(n4),A.CalculateDistance(n2),n4.CalculateDistance(n2))+area(A.CalculateDistance(n2),n2.CalculateDistance(B),A.CalculateDistance(B));
                s2 = S - s1;
            }
        }
        if(n3!=null&&n4!=null) {
            if(l3.LineSegment(n3)&&l4.LineSegment(n4)) {
                s1 = area(D.CalculateDistance(n4),D.CalculateDistance(n3),n4.CalculateDistance(n3));
                s2 = S - s1;
            }
        }
        input(s1,s2);
    }
    public static void input(double s1,double s2) {
        System.out.print("2 ");
        if(s2>s1) {
            DigitalConversion(s1,true);
            DigitalConversion(s2,false);
        }else {
            DigitalConversion(s2,true);
            DigitalConversion(s1,false);
        }
    }
    public static int GetIntersection(Line l,Line l1,Line l2,Line l3,Line l4) {
        boolean flag = false;
        Point m1;Point m2;Point m3;Point m4;
        m1 = l.GetPoint(l1);m2 = l.GetPoint(l2);m3 = l.GetPoint(l3);m4 = l.GetPoint(l4);
        if(m1!=null) {
            if(l1.LineSegment(m1)) {
                sites.add(m1);
            }
        }
        flag = false;
        if(m2!=null) {
            if(l2.LineSegment(m2)) {
                for(Point element : sites) {
                    if(element.getX()==m2.getX()&&element.getY()==m2.getY()) {
                        flag = true;
                    }
                }
                if(flag==false) {
                    sites.add(m2);
                }
            }
        }
        flag = false;
        if(m3!=null) {
            if(l3.LineSegment(m3)) {
                for(Point element : sites) {
                    if(element.getX()==m3.getX()&&element.getY()==m3.getY()) {
                        flag = true;
                    }
                }
                if(flag==false) {
                    sites.add(m3);
                }
            }
        }
        flag = false;
        if(m4!=null) {
            if(l4.LineSegment(m4)) {
                for(Point element : sites) {
                    if(element.getX()==m4.getX()&&element.getY()==m4.getY()) {
                        flag = true;
                    }
                }
                if(flag==false) {
                    sites.add(m4);
                }
            }
        }
        return sites.size();
    }
    
    
    public static void Caculate(Line l,Point a,Point b,Point c) {
        if(l.StraightLine(a)&&l.StraightLine(b)||l.StraightLine(a)&&l.StraightLine(c)||l.StraightLine(b)&&l.StraightLine(c)) {
            System.out.println("The line is coincide with one of the lines");
            System.exit(0);
        }
        int intersection = 0;
        double S = area(a.CalculateDistance(b),b.CalculateDistance(c),c.CalculateDistance(a));
        double s1 = 0;
        double s2 = 0;
        Point pointcenter;Point same1;Point same2;
        if((l.StraightLocation(a)==1&&l.StraightLocation(b)==1&&l.StraightLocation(c)==1)||(l.StraightLocation(a)==-1&&l.StraightLocation(b)==-1&&l.StraightLocation(c)==-1)) {
            intersection = 0;
        }
        if((l.StraightLocation(a)==0&&l.StraightLocation(b)==1&&l.StraightLocation(c)==1)||(l.StraightLocation(a)==0&&l.StraightLocation(b)==-1&&l.StraightLocation(c)==-1)||
          (l.StraightLocation(a)==1&&l.StraightLocation(b)==0&&l.StraightLocation(c)==1)||(l.StraightLocation(a)==-1&&l.StraightLocation(b)==0&&l.StraightLocation(c)==-1)||
          (l.StraightLocation(a)==1&&l.StraightLocation(b)==1&&l.StraightLocation(c)==0)||(l.StraightLocation(a)==-1&&l.StraightLocation(b)==-1&&l.StraightLocation(c)==0)) {
            intersection = 1;
        }
        if((l.StraightLocation(a)==1&&l.StraightLocation(b)==-1&&l.StraightLocation(c)==-1)||(l.StraightLocation(a)==-1&&l.StraightLocation(b)==1&&l.StraightLocation(c)==1)||
          (l.StraightLocation(a)==1&&l.StraightLocation(b)==0&&l.StraightLocation(c)==-1)||(l.StraightLocation(a)==-1&&l.StraightLocation(b)==0&&l.StraightLocation(c)==0)){//a基准点
            intersection = 2;
            pointcenter = a;
            Line n1 = new Line(a,b);Line n2 = new Line(a,c);
            same1 = l.GetPoint(n1);
            same2 = l.GetPoint(n2);
            s1 = area(pointcenter.CalculateDistance(same1),pointcenter.CalculateDistance(same2),same1.CalculateDistance(same2));
            s2 = S-s1;
        }
        if((l.StraightLocation(a)==-1&&l.StraightLocation(b)==1&&l.StraightLocation(c)==-1)||(l.StraightLocation(a)==1&&l.StraightLocation(b)==-1&&l.StraightLocation(c)==1)||
          (l.StraightLocation(a)==1&&l.StraightLocation(b)==-1&&l.StraightLocation(c)==0)||(l.StraightLocation(a)==-1&&l.StraightLocation(b)==1&&l.StraightLocation(c)==0)){//b基准点
            intersection = 2;
            pointcenter = b;
            Line n1 = new Line(b,a);Line n2 = new Line(b,c);
            same1 = l.GetPoint(n1);
            same2 = l.GetPoint(n2);
            s1 = area(pointcenter.CalculateDistance(same1),pointcenter.CalculateDistance(same2),same1.CalculateDistance(same2));
            s2 = S-s1;
        }
        if((l.StraightLocation(a)==1&&l.StraightLocation(b)==1&&l.StraightLocation(c)==-1)||(l.StraightLocation(a)==-1&&l.StraightLocation(b)==-1&&l.StraightLocation(c)==1)||
          (l.StraightLocation(a)==0&&l.StraightLocation(b)==-1&&l.StraightLocation(c)==1)||(l.StraightLocation(a)==0&&l.StraightLocation(b)==1&&l.StraightLocation(c)==-1)){//c基准点
            intersection = 2;
            pointcenter = c;
            Line n1 = new Line(c,a);Line n2 = new Line(b,c);
            same1 = l.GetPoint(n1);
            same2 = l.GetPoint(n2);
            s1 = area(pointcenter.CalculateDistance(same1),pointcenter.CalculateDistance(same2),same1.CalculateDistance(same2));
            s2 = S-s1;
        }
        if(intersection==2) {
            input(s1,s2);
        }else {
            System.out.print(intersection);
        }
    }
    
    public static double area(double a,double b,double c) {
        double C = a+b+c;
        return Math.sqrt((C/2)*(C/2-a)*(C/2-b)*(C/2-c));
    }
    
    public static boolean JudgeQuadrilateral() {//合法四边形
        Line l1 = new Line(A,C);
        if(l1.StraightLocation(B)==l1.StraightLocation(D)) {
            if(!(pointInsideTriangle(A,B,C,D)||pointInsideTriangle(C,A,B,D)||pointInsideTriangle(D,A,B,C))) {
                return true;
            }
        }
        return false;
    }
    
    public static boolean pointInsideTriangle(Point p1,Point p2,Point p3,Point p4) {//判断一个点是否在其他三个点围成的三角形内
        double flag1 = (p1.getX()-p2.getX())*(p1.getY()-p3.getY())-(p1.getY()-p2.getY())*(p1.getX()-p3.getX());
        double flag2 = (p1.getX()-p3.getX())*(p1.getY()-p4.getY())-(p1.getY()-p3.getY())*(p1.getX()-p4.getX());
        double flag3 = (p1.getX()-p4.getX())*(p1.getY()-p2.getY())-(p1.getY()-p4.getY())*(p1.getX()-p2.getX());
        if((flag1<0&&flag2<0&&flag3<0)||(flag1>0&&flag2>0&&flag3>0)) {
            return true;//在里面
        }
        return false;//不在里面
    }
    
    public static void DigitalConversion(double x,boolean flag1) {//输出
        String str = String.format("%.3f",x);
        double nums = Double.parseDouble(str);
        System.out.print(nums);
        if(flag1==true)
            System.out.print(" ");
    }
    
    public static void dataDetection(String alp,int nums) {
        if(!NumberCheckInputIegitimate(alp,nums)) {
            System.out.println("wrong number of points");
            System.exit(0);
        }
        if(A.CoincidenceJudgment(B)||A.CoincidenceJudgment(C)||A.CoincidenceJudgment(D)||B.CoincidenceJudgment(C)||B.CoincidenceJudgment(D)||C.CoincidenceJudgment(D)) {
            System.out.println("points coincide");
            System.exit(0);
        }
    }
    
    public static boolean NumberCheckInputIegitimate(String alp,int nums) {//数量是否正确
        int length = alp.length();
        int count = 0;
        for(int i = 0;i < length;i++)
        {
            if(alp.charAt(i)==',')
                count++;
        }
        if(count!=nums)
        {
            return false;
        }
        return true;
    }
    
    public static boolean CheckInputIegitimate(String alp) {//判断合法性
        String regStr = "([1-5]:((\\+?|-?)(0(\\.0+)?|[1-9]\\d*|[1-9]\\d*\\.\\d+|0\\.\\d*[1-9]\\d*),(\\+?|-?)(0(\\.0+)?|[1-9]\\d*|[1-9]\\d*\\.\\d+|0\\.\\d*[1-9]\\d*) )+(\\+?|-?)(0(\\.0+)?|[1-9]\\d*|[1-9]\\d*\\.\\d+|0.\\d*[1-9]\\d*),(\\+?|-?)(0|[1-9]\\d*|[1-9]\\d*\\.\\d+|0\\.\\d*[1-9]\\d*))( ?)";
        if(Pattern.matches(regStr, alp)) {
            return true;
        }
        return false;
    }
}

class Point{
    private double x = 0;
    private double y = 0;
    
    public Point(double x,double y) {
        this.x = x;
        this.y = y;
    }
    
    public double CalculateDistance(Point p) {//两点距离
        double distance = Math.sqrt(Math.pow(this.x-p.x, 2)+(Math.pow(this.y-p.y, 2)));
        return distance;
    }
    
    public boolean CoincidenceJudgment(Point p) {//判断点重合
        if(this.x==p.getX()&&this.y==p.getY()) {
            return true;
        }
        return false;
    }
    
    public double getX() {
        return this.x;
    }
    
    public double getY() {
        return this.y;
    }
    
    public double getSlope(Point p) {
        if(this.getX()-p.getX()!=0) {
            return (this.getY()-p.getY())/(this.getX()-p.getX());
        }
        return -99999999;
    }
}

class Line{
    private Point p1;
    private Point p2;
    
    public Line(Point p1,Point p2) {
        this.p1 = p1;
        this.p2 = p2;
    }
    
    public double getSlope() {
        if(p1.getX()-p2.getX()!=0) {
            return (p1.getY()-p2.getY())/(p1.getX()-p2.getX());
        }
        return -9999999;//斜率无穷大
    }
    
    public boolean JudgeParallel(Line line) {//判断是否平行
        if(this.getSlope()==line.getSlope()) {
            return true;
        }
        return false;
    }
    
    public double GetIncludedAngle(Line l) {//获得两直线夹角度数(正弦值)
        double vectorx1 = this.p2.getX()-this.p1.getX();
        double vectory1 = this.p2.getY()-this.p1.getY();
        double vectorx2 = l.p2.getX()-l.p1.getX();
        double vectory2 = l.p2.getY()-l.p1.getY();
        return Math.sqrt(1-Math.pow(Math.abs(vectorx1*vectorx2+vectory1*vectory2)/(Math.sqrt(Math.pow(vectorx1, 2)+Math.pow(vectory1, 2))*Math.sqrt(Math.pow(vectorx2, 2)+Math.pow(vectory2, 2))),2));
    }
    
    public Point GetPoint(Line l) {//返回两直线交点
        if(this.JudgeParallel(l)) {
            return null;
        }
        double A1 = p1.getY()-p2.getY();
        double B1 = p2.getX()-p1.getX();
        double C1 = (p1.getX()-p2.getX())*p1.getY()-(p1.getY()-p2.getY())*p1.getX();
        double A2 = l.p1.getY()-l.p2.getY();
        double B2 = l.p2.getX()-l.p1.getX();
        double C2 = (l.p1.getX()-l.p2.getX())*l.p1.getY()-(l.p1.getY()-l.p2.getY())*l.p1.getX();
        double x = (-C1*B2+B1*C2)/(A1*B2-A2*B1);
        double y = (-A1*C2+A2*C1)/(A1*B2-A2*B1);
        return new Point(x,y);
    }
    
    public boolean LineSegment(Point p) {
        if(p.getX()>=Math.min(this.p1.getX(), this.p2.getX())&&p.getX()<=Math.max(this.p1.getX(), this.p2.getX())&&
           p.getY()>=Math.min(this.p1.getY(),this.p2.getY())&&p.getY()<=Math.max(this.p1.getY(),this.p2.getY())){
            return true;
        }
        return false;
    }
    
    public boolean StraightLine(Point p) {//判断点是否在直线上
        double A1 = p1.getY()-p2.getY();
        double B1 = p2.getX()-p1.getX();
        double C1 = (p1.getX()-p2.getX())*p1.getY()-(p1.getY()-p2.getY())*p1.getX();
        if(A1*p.getX()+B1*p.getY()+C1==0) {
            return true;
        }
        return false;
    }
    
    public int StraightLocation(Point p) {//判断直线位置，上面返回1，中间0，下面-1
        double A1 = p1.getY()-p2.getY();
        double B1 = p2.getX()-p1.getX();
        double C1 = (p1.getX()-p2.getX())*p1.getY()-(p1.getY()-p2.getY())*p1.getX();
        if(A1*p.getX()+B1*p.getY()+C1>0) {
            return 1;
        }else if(A1*p.getX()+B1*p.getY()+C1==0){
            return 0;
        }
        return -1;
    }
    
    public boolean newLineSegment(Point p) {//判断点是否在该线段上
        if(LineSegment(p)&&StraightLine(p)) {
            return true;
        }
        return false;
    }
}

 

 

 

采坑心得：

（1） 题目所给的四边形的顶点是按照顺序输入的，所以在做任何计算和判断之前，先判断凸四边形是否合法，判断凸四边形合法的方式是连接AC，若BD在AC的异侧即为该四边形合法

（2）关于直线分割多边形的问题，目前我认为最好的方法还是穷举法，四边形有4条边，那么有两个交点的情况就是C（4，2），将每种情况列举出来，拆分成几个三角形求面积

（3）限定保留小数的解决方法：先转换成字符串再转换成double型输出即可，这样做的好处就是不用考虑存在小数点后面全是0的问题

 

 （4）此类问题的正则表达式为：

（5）注意判断顺序

改进建议：

（1）main类的耦合性依然太强，应当可以设计三角形类，四边形类，格式输出类等类来降低main类的耦合性

（2）类中的方法不够完善，main类的很多方法应该是点或线类的方法，在设计上存在问题

---

链表

源码设计解释：

 接口：

 

 

节点类：

 

节点类包括数据域和指针域

链表类：

 

其中head为头指针，tail为尾指针

源码：

package Linkedlist;

interface LinearListInterface<E> {//泛型接口
    public boolean isEmpty();
    public int size();
    public E get(int index);
    public void remove(int index);
    public void add(int index, E theElement);
    public void add(E  element);
    public void printList();    
}
//LinkedList class
class LList<E> implements LinearListInterface<E>{
    private Node<E> head;
    private Node<E> tail;
    private Node<E> curr;
    private int size;
    @Override
    public boolean isEmpty() {//判断当前节点是否为空节点
        // TODO Auto-generated method stub
        if(this.curr==null) {
            return true;
        }
        return false;
    }
    @Override
    public int size() {
        // TODO Auto-generated method stub
        return this.size;
    }
    @Override
    public E get(int index) {//获得第Index节点的值
        // TODO Auto-generated method stub
        int count = 0;
        if(index>=0&&index<=size) {
            this.curr = head;
            while(count<index) {
                this.curr = this.curr.next;
                count++;
            }
            return this.curr.o;//返回当前节点
        }
        return null;
    }
    @Override
    public void remove(int index) {
        // TODO Auto-generated method stub
        int count = 0;
        if(index>=0&&index<=size) {
            if(index==0) {//删除头部
                this.head = this.head.next;
                this.size--;
            }else {
                this.curr = this.head;
                while(count<index-1) {
                    this.curr = this.curr.next;
                    count++;
                }
                this.curr.next = this.curr.next.next;
            }
            this.size--;
        }
        
    }
    @Override
    public void add(int index, E theElement) {//任意位置添加节点
        // TODO Auto-generated method stub
        int count = 0;
        if(index>=0&&index<=this.size) {
            if(index==0) {
                this.head = new Node<E>(theElement,this.head);//如果添加在头部，theElement成为新头部
            }else {
                this.curr = head;
                while(count<index-1) {//找到要添加节点的位置
                    this.curr = this.curr.next;
                    count++;
                }
                this.curr.next = new Node<E>(theElement,this.curr.next);
            }
            this.size++;
        }
        
    }
    @Override
    public void add(E element) {//尾部添加节点
        // TODO Auto-generated method stub
        Node<E> node =new Node<E>(element,null);//新节点    
        this.curr = this.tail;//
        this.tail = node;
        if(isEmpty()) {
            head = node;
        }else{
            curr.next = node;
        }
        this.size++;
    }
    @Override
    public void printList() {
        // TODO Auto-generated method stub
        for(int i = 0;i<this.size;i++) {
            System.out.print(get(i).toString()+" ");
        }
    }

}
//Node

class Node<E>{//节点
        public E o;//数据域
        public Node<E> next;//指针域
        
        public Node(E o,Node<E> next) {//构造器
            this.o = o;
            this.next = next;
        }
}


public class Lianbiao {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        LList<Integer> list = new LList<Integer>();
        for(int i = 0;i<10;i++) {
            list.add(i);
        }
        list.printList();//输出链表
        list.remove(12);//删除第四个节点
        System.out.println("\n删除第四个节点后的链表:");
        list.printList();//输出链表
        list.add(4, 4);//第四个节点添加4
        System.out.println("\n增加第四个节点后的链表:");
        list.printList();//输出链表
    }
}

采坑心得：

    链表的结构很简单，就是一个个节点连接在一起，形成一个完整的链条，每个节点包含2部分，数据域，和一个指向下一个节点引用的指针next,具体的更详细的大家可以参考相关资料解释，再说说删除操作，同样需要找到数据所在的位置，然后进行删除，不同的是，删除的时候，链表只需要改变一下前后节点的引用关系即可，就完成了节点的删除，而没有像数组那样触发一次全部数据的移动，从这个描述来看，链表在进行删除的时候，速度比数组快。

改进建议：

不能够自定义实现链表，应当做适当修改。

---

期中考试分析

点与线（类设计）

源码设计解释：

 

 源码：

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner in = new Scanner(System.in);
        double px = in.nextDouble();
        double py = in.nextDouble();
        double qx = in.nextDouble();
        double qy = in.nextDouble();
        String color = in.next();
        if(px<=0||px>200||py<=0||py>200||qx<=0||qx>200||qy<=0||qy>200) {
            System.out.println("Wrong Format");
            System.exit(0);
        }
        Point p = new Point(px,py);
        Point q = new Point(qx,qy);
        Line l = new Line(p,q,color);
        System.out.println("The line's color is:"+l.getColor());
        l.display();
        System.out.printf("The line's length is:%.2f",l.getDistance());
    }

}

class Point{
    private double x = 0;
    private double y = 0;
    
    public Point(double x,double y) {
        this.x = x;
        this.y = y;
    }
    
    public void display() {
        System.out.println("The line's begin point's Coordinate is:");
        System.out.printf("(%.2f,%.2f)",this.x,this.y);
    }
    
    public double getX() {
        return this.x;
    }
    
    public double getY() {
        return this.y;
    }
    
    public void setX(double x) {
        this.x = x;
    }
    
    public void setY(double y) {
        this.y = y;
    }
}

class Line{
    private Point point1;
    private Point point2;
    private String color;
    
    public Line(Point p1,Point p2,String color) {
        this.point1 = p1;
        this.point2 = p2;
        this.color = color;
    }
    
    public Point getPoint1() {
        return point1;
    }
    
    public Point getPoint2() {
        return point2;
    }
    
    public void setPoint1(Point point1) {
        this.point1 = point1;
    }
    
    public void setPoint2(Point point2) {
        this.point2 = point2;
    }
    
    public String getColor() {
        return color;
    }
    
    public void setColor(String color) {
        this.color = color;
    }
    
    public double getDistance() {
        return Math.sqrt(Math.pow(this.point1.getX()-this.point2.getX(), 2)+Math.pow(this.point1.getY()-this.point2.getY(), 2));
    }
    
    public void display() {
        System.out.println("The line's begin point's Coordinate is:");
        System.out.printf("(%.2f,%.2f)\n",this.point1.getX(),this.point1.getY());
        System.out.println("The line's end point's Coordinate is:");
        System.out.printf("(%.2f,%.2f)\n",this.point2.getX(),this.point2.getY());
    }
}

说明：

最基础的类的设计，通过创建对象然后调用类中的方法实现对点和线信息的输出

下面对点线面问题重构，新增一个抽象类Element，点类和线类成为该类的子类，再创建一个面类，也是Element的子类

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner in = new Scanner(System.in);
        double px = in.nextDouble();
        double py = in.nextDouble();
        double qx = in.nextDouble();
        double qy = in.nextDouble();
        String color = in.next();
        if(px<=0||px>200||py<=0||py>200||qx<=0||qx>200||qy<=0||qy>200) {
            System.out.println("Wrong Format");
            System.exit(0);
        }
        Point p = new Point(px,py);
        Point q = new Point(qx,qy);
        Line l = new Line(p,q,color);
        Plane plane = new Plane(color);
        Element element = p;
        p.display();
        element = q;
        q.display();
        element = l;
        l.display();
        element = plane;
        plane.display();
    }

}

class Point extends Element{
    private double x = 0;
    private double y = 0;
    
    public Point(double x,double y) {
        this.x = x;
        this.y = y;
    }
    @Override
    public void display() {
        System.out.printf("(%.2f,%.2f)\n",this.x,this.y);
    }
    
    public double getX() {
        return this.x;
    }
    
    public double getY() {
        return this.y;
    }
    
    public void setX(double x) {
        this.x = x;
    }
    
    public void setY(double y) {
        this.y = y;
    }
}

class Line extends Element{
    private Point point1;
    private Point point2;
    private String color;
    
    public Line(Point p1,Point p2,String color) {
        this.point1 = p1;
        this.point2 = p2;
        this.color = color;
    }
    
    public Point getPoint1() {
        return point1;
    }
    
    public Point getPoint2() {
        return point2;
    }
    
    public void setPoint1(Point point1) {
        this.point1 = point1;
    }
    
    public void setPoint2(Point point2) {
        this.point2 = point2;
    }
    
    public String getColor() {
        return color;
    }
    
    public void setColor(String color) {
        this.color = color;
    }
    
    public double getDistance() {
        return Math.sqrt(Math.pow(this.point1.getX()-this.point2.getX(), 2)+Math.pow(this.point1.getY()-this.point2.getY(), 2));
    }
    @Override
    public void display() {
        System.out.println("The line's color is:"+this.getColor());
        System.out.println("The line's begin point's Coordinate is:");
        System.out.printf("(%.2f,%.2f)\n",this.point1.getX(),this.point1.getY());
        System.out.println("The line's end point's Coordinate is:");
        System.out.printf("(%.2f,%.2f)\n",this.point2.getX(),this.point2.getY());
        System.out.printf("The line's length is:%.2f",this.getDistance());
        System.out.printf("\n");
    }
}

abstract class Element{
    public void display() {
        
    }
}

class Plane extends Element{
    private String color;
    
    public Plane(String color) {
        this.color = color;
    }
    
    public String getColor() {
        return color;
    }
    
    public void setColor() {
        this.color = color;
    }
    
    public void display() {
        System.out.println("The Plane's color is:"+this.getColor());
    }
}

 说明：

在主方法内，定义两个Point对象、一个Line对象和一个Plane对象，依次从键盘输入两个Point对象的起点、终点坐标和颜色值（Line对象和Plane对象颜色相同），然后定义一个Element类的引用，分别使用该引用调用以上四个对象的display()方法，这就实现了多态特性。

 下面在“点与线”题目基础上，对题目的类设计进行重构，增加容器类保存点、线、面对象，并对该容器进行相应增、删、遍历操作。

import java.util.ArrayList;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        GeometryObject geo = new GeometryObject();
        Scanner in = new Scanner(System.in);
        while(true) {
            int choice = in.nextInt();
            if(choice==0) {
                break;
            }
            switch(choice) {
                case 1:
                    double px = in.nextDouble();
                    double py = in.nextDouble();
                    if(px<=0||px>200||py<=0||py>200) {
                        System.out.println("Wrong Format");
                        System.exit(0);
                    }
                    geo.add(new Point(px,py));
                    break;
                case 2:
                    double ppx = in.nextDouble();
                    double ppy = in.nextDouble();
                    double qx = in.nextDouble();
                    double qy = in.nextDouble();
                    String color = in.next();
                    if(ppx<=0||ppx>200||ppy<=0||ppy>200||qx<=0||qx>200||qy<=0||qy>200) {
                        System.out.println("Wrong Format");
                        System.exit(0);
                    }
                    Point p = new Point(ppx,ppy);
                    Point q = new Point(qx,qy);
                    Line l = new Line(p,q,color);
                    geo.add(l);
                    break;
                case 3:
                    String planecolor = in.next();
                    Plane plane = new Plane(planecolor);
                    geo.add(plane);
                    break;
                case 4:
                    int choose = in.nextInt();
                    geo.remove(choose);
                    break;
                default:
                    break;
            }
        }
        for(Element element : geo.getList()) {
            element.display();
        }
    }

}

class Point extends Element{
    private double x = 0;
    private double y = 0;
    
    public Point(double x,double y) {
        this.x = x;
        this.y = y;
    }
    @Override
    public void display() {
        System.out.printf("(%.2f,%.2f)\n",this.x,this.y);
    }
    
    public double getX() {
        return this.x;
    }
    
    public double getY() {
        return this.y;
    }
    
    public void setX(double x) {
        this.x = x;
    }
    
    public void setY(double y) {
        this.y = y;
    }
}

class Line extends Element{
    private Point point1;
    private Point point2;
    private String color;
    
    public Line(Point p1,Point p2,String color) {
        this.point1 = p1;
        this.point2 = p2;
        this.color = color;
    }
    
    public Point getPoint1() {
        return point1;
    }
    
    public Point getPoint2() {
        return point2;
    }
    
    public void setPoint1(Point point1) {
        this.point1 = point1;
    }
    
    public void setPoint2(Point point2) {
        this.point2 = point2;
    }
    
    public String getColor() {
        return color;
    }
    
    public void setColor(String color) {
        this.color = color;
    }
    
    public double getDistance() {
        return Math.sqrt(Math.pow(this.point1.getX()-this.point2.getX(), 2)+Math.pow(this.point1.getY()-this.point2.getY(), 2));
    }
    @Override
    public void display() {
        System.out.println("The line's color is:"+this.getColor());
        System.out.println("The line's begin point's Coordinate is:");
        System.out.printf("(%.2f,%.2f)\n",this.point1.getX(),this.point1.getY());
        System.out.println("The line's end point's Coordinate is:");
        System.out.printf("(%.2f,%.2f)\n",this.point2.getX(),this.point2.getY());
        System.out.printf("The line's length is:%.2f",this.getDistance());
        System.out.printf("\n");
    }
}

abstract class Element{
    public void display() {
        
    }
}

class Plane extends Element{
    private String color;
    
    public Plane(String color) {
        this.color = color;
    }
    
    public String getColor() {
        return color;
    }
    
    public void setColor() {
        this.color = color;
    }
    
    public void display() {
        System.out.println("The Plane's color is:"+this.getColor());
    }
}

class GeometryObject{
    private ArrayList<Element> list = new ArrayList<>();
    
    public void add(Element element) {
        list.add(element);
    }
    
    public void remove(int index) {
        if(index<=list.size()) {
            list.remove(index-1);
        }
    }
    
    public ArrayList<Element> getList(){
        return list;    
    }
}

说明：

 ArrayList相当于一个对象容器，里面存入的是Element类型的，这就能够完成增、删、遍历操作。

采坑心得：

 （1）给有相同性质的类设计一个父类是一个很好的编程思维，再进行相关操作的时候使用向上造型实现多态特性，这不仅能提高代码的复用性还能使代码更加的简洁，编程效率更加高效

（2）使用泛型也是一种很好的编程思维，能够实现增、删、遍历操作。对任意的一个对象都能够修改。

---

总结:

学会了什么：

1.通过对本阶段综合性总结，我对Java的基础语法（选择、函数、字符字符串相关操作、循环、方法、数组）有了更深层次的理解

2.对类与对象的设计原则有了更深层次的理解，了解了继承原则和多态特性，并能在实际编程加以应用

3.了解了什么是接口、并能熟练应用

还需要改进加强的地方：

1.考虑问题不够全面

2.主函数不能做到完全解耦

3.算法不够精确不够简单

 

 

 

 

 

 

 

 

 

 

 

 

 

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