第八周上机+练习

1、编写一个简单程序,要求数组长度为5,分别赋值10,20,30,40,50,在控制台输出该数组的值。(知识点:数组定义和创建、一维数组初始化)[必做题]• 

package week8;


public class P1 {


/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
int a[]={10,20,30,40,50};
for (int i = 0; i < a.length; i++) {
System.out.println(a[i]);
}


}


}

 

 

 

 

 

 

 



2、将一个字符数组的值(neusofteducation)拷贝到另一个字符数组中。(知识点:数组复制) [必做题]• 
package week8;

public class P2 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        char a[]={'n','e','u','s','o','f','t','e','d','u','c','a','t','i','o','n'};
        char b[]=new char [a.length];
        System.arraycopy(a,0,b,0,a.length);
        for (int i = 0; i < b.length; i++) {
            System.out.print(b[i]);
        }
    }

}

 

 

 



3、给定一个有9个整数(1,6,2,3,9,4,5,7,8)的数组,先排序,然后输出排序后的数组的值。(知识点:Arrays.sort排序、冒泡排序)
package week8;

import java.util.Arrays;

public class P3 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int a[]={1,6,2,3,9,4,5,7,8};
        Arrays.sort(a);
        for (int i = 0; i < a.length; i++) {
            System.out.println(a[i]);
        }

    }

}

 

 



4、 输出一个double型二维数组(长度分别为5、4,值自己设定)的值。(知识点:数组定义和创建、多维数组初始化、数组遍历)
package week8;

public class P4 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        double a[][]=new double[5][4];
        for (int i = 0; i < a.length; i++) {
            for (int j = 0; j < a[i].length; j++) {
                a[i][j]=i*j;
            }
        }
        for (int i = 0; i < a.length; i++) {
            System.out.println(" ");
            for (int j = 0; j < a[i].length; j++) {
                System.out.print(a[i][j]+"   ");
            }
        }
    }

}

 

 

 


 
5、 在一个有8个整数(18,25,7,36,13,2,89,63)的数组中找出其中最大的数及其下标。(知识点:数组遍历、数组元素访问) [必做题]•
package week8;

public class P5 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int a[]={18,25,7,36,13,2,89,63};
        int max=0;
        int b=0;
        for (int i = 0; i < a.length; i++) {
            if(a[i]>max)
            {
                max=a[i];
                b=i;
            }
        }
        System.out.println("最大值为"+max);
        System.out.println("下标为"+b);
    }

}

 

 



作业
6、将一个数组中的元素逆序存放(知识点:数组遍历、数组元素访问) [选作题]•
package week8;

import java.util.Scanner;

public class W1 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int a[]=new int[5] ;
        Scanner input=new Scanner(System.in);
        for (int i = a.length; i > 0; i--) {
            a[i-1]=input.nextInt();
        }
        for (int i = 0; i < a.length; i++) {
            System.out.println(a[i]);
        }

    }

}

 

 

 



7. 将一个数组中的重复元素保留一个其他的清零。(知识点:数组遍历、数组元素访问) [选作题]课后作业• 

package week8;

import java.util.Scanner;

public class W2 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int a[]=new int [5];
        Scanner input=new Scanner(System.in);
        for (int i = 0; i < a.length; i++) {
            a[i]=input.nextInt();
        }
        for (int i = 0; i < a.length; i++) {
            for (int j = i+1; j < a.length; j++) {
                if(a[i]==a[j]&&a[i]!=0)
                {
                    a[j]=0;
                }
            }
            
            
        }
        for (int i = 0; i < a.length; i++) {
            System.out.println(a[i]);
        }
    }

}

 

 


8、给定一维数组{ -10,2,3,246,-100,0,5},计算出数组中的平均值、最大值、最小值。(知识点:数组遍历、数组元素访问)
package week8;

public class W3 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int a[]={-10,2,3,246,-100,0,5};
        int max=0;
        int min=0;
        int sum=0;
        for (int i = 0; i < a.length; i++) {
            if (a[i]>max)
            {
                max=a[i];
            }
            if (a[i]<min)
            {
                min=a[i];
            }
            sum+=a[i];
        }
        System.out.println("最大值是"+max);
        System.out.println("最小值是"+min);
        System.out.println("平均数是"+sum/a.length);

    }

}

 

 

 


9、使用数组存放裴波那契数列的前20项 ,并输出
package week8;

public class W4 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int a[]=new int [20];
        a[0]=1;
        int x=1;
        int y=1;
        int sum=1;
        for (int i = 1; i < a.length; i++) {
            a[i]=sum;
            sum=x+y;
            x=y;
            y=sum;
        }
        for (int i = 0; i < a.length; i++) {
            System.out.println(a[i]+" ");
        }

    }

}

 

 



10、生成一个长度为10的随机整数数组(每个数都是0-100之间),输出,排序后,再输出
package week8;

import java.util.Random;

public class W5 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Random input = new Random();
        int a = 0;
        int x = 0;
        int arr[]=new int[10];
        for(int i = 0;i<arr.length;i++) {
            a = input.nextInt(100);
            arr[i]=a;
        System.out.print(arr[i]+" ");
        }
        System.out.println();
        for(int i = 0;i<arr.length-1-i;i++) {
            for(int j = 0;j<arr.length-1-i;j++) {
            if(arr[j]>arr[j+1]) {
                x = arr[j];
                arr[j] = arr[j+1];
                arr[j+1] = x;
            }
            }
        }
        for(int i = 0;i<arr.length;i++) {
        System.out.print(arr[i]+" ");
        }

    }

}

 

 

posted @ 2021-04-27 11:52  崔明月  阅读(33)  评论(0编辑  收藏  举报