Java入门——day48 - 戈瑾

Java入门——day48

1.三维坐标向量类

设计一个描述三维坐标的向量类vector3D，成员如下：

数据成员：

三个坐标x，y，z，float类型，私有访问属性

公有函数成员：

三个参数均有默认值的构造函数，默认值为0，0，0；
完成输入输出，输出格式为(x, y, z)；
完成加法+、减法-、数乘*运算；

在主函数中定义两个vector3D类对象v1，v2，均不带参数，之后输入数字1或2选择为v1输入赋值，还是为v1和v2输入赋值，对v1和v2进行加、减运算，对v1进行数乘运算，乘数由用户输入，最后输出三种运算结果。

 1 import java.util.Scanner;
 2 //三维向量坐标类
 3 public class Vector3D {
 4     private float x;
 5     private float y;
 6     private float z;
 7     public Vector3D() {
 8         this.x=0;
 9         this.y=0;
10         this.z=0;
11     }
12     public Vector3D(float x, float y, float z) {
13         this.x = x;
14         this.y = y;
15         this.z = z;
16     }
17     public void input() {
18         Scanner in=new Scanner(System.in);
19         x=in.nextFloat();
20         y=in.nextFloat();
21         z=in.nextFloat();
22     }
23     public void display() {
24         System.out.println("("+x+"，"+y+"，"+z+")");
25     }
26     //加法
27     public Vector3D add(Vector3D v) {
28         float a=x+v.x;
29         float b=y+v.y;
30         float c=z+v.z;
31         Vector3D p=new Vector3D(a,b,c);
32         return p;
33     }
34     //减法
35     public Vector3D sub(Vector3D v) {
36         float a=x-v.x;
37         float b=y-v.y;
38         float c=z-v.z;
39         Vector3D p=new Vector3D(a,b,c);
40         return p;
41     }
42     //数乘
43     public Vector3D mul(float n) {
44         float a=x*n;
45         float b=y*n;
46         float c=z*n;
47         Vector3D p=new Vector3D(a,b,c);
48         return p;
49     }
50     public static void main(String[] args) {
51         int n;
52         Vector3D v1=new Vector3D();
53         Vector3D v2=new Vector3D();
54         Scanner in=new Scanner(System.in);
55         System.out.println("1.为三维向量v1赋值并进行数乘运算");
56         System.out.println("2.为三维向量v1、v2赋值并进行加、减运算");
57         System.out.print("请输入你要进行的操作编号：");
58         n=in.nextInt();
59         if(n==1) {
60             float t;
61             Vector3D v;
62             System.out.print("请输入v1的三维坐标：");
63             v1.input();
64             System.out.print("请输入乘数：");
65             t=in.nextFloat();
66             v=v1.mul(t);
67             System.out.print("数乘结果为：");
68             v.display();
69         }
70         if(n==2) {
71             System.out.print("请输入v1的三维坐标：");
72             v1.input();
73             System.out.print("请输入v2的三维坐标：");
74             v2.input();
75             System.out.print("相加结果为：");
76             (v1.add(v2)).display();
77             System.out.print("相减结果为：");
78             (v1.sub(v2)).display();
79         }
80     }
81 }

2.电子钟

设计一款电子钟类，用于显示时、分、秒

含有形参有默认值的默认构造函数；
前缀++ 和后缀—用于调整时间，每次调整均对秒进行调整，若秒满60，则分加1，若分满60则时加1，时满24，则清零重新开始；
设置函数用于输入（设定）时间；
设置函数用于输出时间。

  1 import java.util.Scanner;
  2 //电子钟类
  3 public class Time {
  4     private int hour;
  5     private int minute;
  6     private int second;
  7     public Time() {
  8         this.hour = 0;
  9         this.minute = 0;
 10         this.second = 0;
 11     }
 12     public Time(int hour, int minute, int second) {
 13         this.hour = hour;
 14         this.minute = minute;
 15         this.second = second;
 16     }
 17     // 正计时
 18     public void zheng() {
 19         ++second;
 20         if (second >= 60) {
 21             second = 0;
 22             ++minute;
 23             if (minute >= 60) {
 24                 minute = 0;
 25                 ++hour;
 26                 hour %= 24;
 27             }
 28         }
 29     }
 30     // 倒计时
 31     public void dao() {
 32         second--;
 33         if (second < 0) {
 34             minute--;
 35             second = 59;
 36         }
 37         if (minute < 0) {
 38             minute = 59;
 39             hour--;
 40         }
 41         if (hour < 0) {
 42             hour = 23;
 43         }
 44     }
 45     // 输入电子钟
 46     public void input() {
 47         Scanner in = new Scanner(System.in);
 48         hour = in.nextInt();
 49         minute = in.nextInt();
 50         second = in.nextInt();
 51     }
 52     // 输出电子钟
 53     public void output() {
 54         System.out.println(hour + ":" + minute + ":" + second);
 55     }
 56     public boolean dengYu(Time t) {
 57         if (hour == t.hour && minute == t.minute && second == t.second) {
 58             return true;
 59         } else {
 60             return false;
 61         }
 62     }
 63     public static void main(String[] args) throws InterruptedException {
 64         int n;
 65         Scanner in = new Scanner(System.in);
 66         // 菜单打印
 67         System.out.println("功能选择：");
 68         System.out.println("*********");
 69         System.out.println("1.钟表");
 70         System.out.println("2.正计时");
 71         System.out.println("3.倒计时");
 72         System.out.println("*********");
 73         System.out.print("请输入你的选择：");
 74         n = in.nextInt();
 75         if (n == 1) {
 76             System.out.print("请先校准时间：");
 77             Time t = new Time();
 78             t.input();
 79             while (true) {
 80                 t.output();
 81                 t.zheng();
 82                 Thread.sleep(2000);
 83             }
 84         }
 85         if (n == 2) {
 86             Time t = new Time();
 87             while (true) {
 88                 t.output();
 89                 t.zheng();
 90                 Thread.sleep(2000);
 91             }
 92         }
 93         if (n == 3) {
 94             Time t1 = new Time();
 95             Time t2 = new Time();
 96             System.out.print("请输入时间：");
 97             t1.input();
 98             while (true) {
 99                 t1.output();
100                 t1.dao();
101                 Thread.sleep(2000);
102                 if (t1.dengYu(t2)) {
103                     break;
104                 }
105             }
106             System.out.println("STOP!");
107         }
108     }
109 }

3.分数类

  1 import java.util.Scanner;
  2 //分数类
  3 public class Fraction {
  4     private int x;
  5     private int y;
  6     public Fraction() {
  7     }
  8     public Fraction(int x, int y) {
  9         this.x = x;
 10         this.y = y;
 11     }
 12     // 分数的输入
 13     public void input() {
 14         Scanner in = new Scanner(System.in);
 15         x = in.nextInt();
 16         y = in.nextInt();
 17     }
 18     // 分数的输出
 19     public void output() {
 20 
 21         if (y < 0) {
 22             x = -x;
 23             y = -y;
 24         }
 25         System.out.println(x + "/" + y);
 26     }
 27     // 求分子、分母的最大公因数
 28     public static int max(int a, int b) {
 29         int c = 0;
 30         while (a % b != 0) {
 31             c = a % b;
 32             a = b;
 33             b = c;
 34         }
 35         return c;
 36     }
 37     // 化简分数
 38     public Fraction simp() {
 39         int p = max(x, y);
 40         x = x / p;
 41         y = y / p;
 42         Fraction f = new Fraction(x, y);
 43         return f;
 44     }
 45     // 分数的加法
 46     public Fraction add(Fraction f) {
 47         int p = max(x * f.y + y * f.x, y * f.y);
 48         if (y == f.y) {
 49             Fraction c = new Fraction(x + f.x, y);
 50             return c;
 51         } else {
 52             Fraction c = new Fraction((x * f.y + y * f.x) / p, (y * f.y) / p);
 53             return c;
 54         }
 55     }
 56     // 分数的减法
 57     public Fraction sub(Fraction f) {
 58         int p = max(x * f.y - y * f.x, y * f.y);
 59         if (y == f.y) {
 60             Fraction c = new Fraction(x - f.x, y);
 61             return c;
 62         } else {
 63             Fraction c = new Fraction((x * f.y - y * f.x) / p, (y * f.y) / p);
 64             return c;
 65         }
 66     }
 67     // 分数的数乘
 68     public Fraction mul(int n) {
 69         int p = max(x * n, y);
 70         Fraction c = new Fraction((x * n) / p, y / p);
 71         return c;
 72     }
 73 
 74     // 判断关系：分数1==分数2
 75     public boolean dengYu(Fraction c) {
 76         int p1 = max(x, y);
 77         int p2 = max(c.x, c.y);
 78         if (x / p1 == c.x / p2 && y / p1 == c.y / p2) {
 79             return true;
 80         } else {
 81             return false;
 82         }
 83     }
 84     // 判断关系：分数1!=分数2
 85     public boolean buDengYu(Fraction c) {
 86         int p1 = max(x, y);
 87         int p2 = max(c.x, c.y);
 88         if (x / p1 == c.x / p2 && y / p1 == c.y / p2) {
 89             return false;
 90         } else {
 91             return true;
 92         }
 93     }
 94     // 判断关系：分数1>=分数2
 95     public boolean daYu(Fraction c) {
 96         int n1 = x * c.y;
 97         int n2 = y * c.x;
 98         if (n1 >= n2) {
 99             return true;
100         } else {
101             return false;
102         }
103     }
104     // 判断关系：分数1<=分数2
105     public boolean xiaoYu(Fraction c) {
106         int n1 = x * c.y;
107         int n2 = y * c.x;
108         if (n1 <= n2) {
109             return true;
110         } else {
111             return false;
112         }
113     }
114     public static void main(String[] args) {
115         int t, n;
116         Fraction f1 = new Fraction();
117         Fraction f2 = new Fraction();
118         // 菜单打印
119         System.out.println("功能选择：");
120         System.out.println("**************");
121         System.out.println("1.分数加法");
122         System.out.println("2.分数减法");
123         System.out.println("3.分数数乘");
124         System.out.println("4.分数关系比较");
125         System.out.println("**************");
126         System.out.print("请输入你的选择：");
127         Scanner in = new Scanner(System.in);
128         t = in.nextInt();
129         if (t == 1) {
130             System.out.print("请输入分数1：");
131             f1.input();
132             System.out.print("请输入分数2：");
133             f2.input();
134             System.out.print("相加结果：");
135             (f1.add(f2)).output();
136         }
137         if (t == 2) {
138             System.out.print("请输入分数1：");
139             f1.input();
140             System.out.print("请输入分数2：");
141             f2.input();
142             System.out.print("相减结果：");
143             (f1.sub(f2)).output();
144         }
145         if (t == 3) {
146             System.out.print("请输入分数：");
147             f1.input();
148             System.out.print("请输入乘数：");
149             n = in.nextInt();
150             System.out.print("数乘结果：");
151             (f1.mul(n)).output();
152         }
153         if (t == 4) {
154             System.out.print("请输入分数1：");
155             f1.input();
156             System.out.print("请输入分数2：");
157             f2.input();
158             if (f1.daYu(f2)) {
159                 System.out.print("分数1==分数2");
160             }
161             if (f1.buDengYu(f2)) {
162                 System.out.println("分数1!=分数2");
163             }
164             if (f1.daYu(f2)) {
165                 System.out.println("分数1>=分数2");
166             }
167             if (f1.xiaoYu(f2)) {
168                 System.out.println("分数1<=分数2");
169             }
170         }
171     }
172 }

posted on 2020-08-22 21:44 戈瑾阅读(201) 评论(0) 收藏举报

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