第六周课后作业

1.定义长度为5的整型数组,输入他们的值,用冒泡排序后输出.

package sss;

public class khzy {
    public static void main(String[] args) {
        // TODO Auto-generated method stubint 
        int[] arr = {3,5,9,7,1};
        for (int i = 0; i < arr.length; i++) {
        for (int j = 0; j < arr.length-1-i; j++) {
            int num = 0;
            if(arr[j] > arr[j+1]){
                num = arr[j];
                arr[j]= arr[j+1];
                arr[j+1] = num;
                }
            }
        }
        for (int i : arr) {
            System.out.println(i);
            }
        }
}

 2.定义数组{34,22,35,67,45,66,12,33},输入一个数a,查找在数组中是否存在,如果存在,输出下标,不存在输出"not found"

package sss;
Scanner input=new Scanner(System.in);
public class khzy {
    public static void main(String[] args) {
        // TODO Auto-generated method stubint 
            boolean  A=false;
            int[] x=new int[]{34,22,35,67,45,66,12,33};
            System.out.print("请输入需要查找的数");
            int a=input.nextInt();
            for(int i=0;i<x.length;i++){
                if(x[i]==a){
                    System.out.println("该数存在于数组中下标为"+i);
                     A=true;
                }
            } if(A==false){
                System.out.println("not found");
            }
    }
}

3.以矩阵的形式输出一个double型二维数组（长度分别为5、4，值自己设定）的值。

package sss;

public class khzy {
    public static void main(String[] args) {
        // TODO Auto-generated method stubint 
        double[][]arr={{0,0,0,0},{0,1,1,0},
                {0,1,1,0},{0,1,1,0},
                {0,0,0,0}};
        for(int i=0;i<arr.length;i++){
            System.out.println();
            for(int j=0;j<arr.length-1;j++){
                System.out.print(arr[i][j]+" ");
            }
        }
    }
}

4.定义一个二维数组(长度分别为3,4,值自己设定),求该二维数组的最大值

package sss;

public class khzy {
    public static void main(String[] args) {
        // TODO Auto-generated method stubint 
        int arr[][]={{1,2,3},{4,5,6},
                {7,8,9},{10,11,12}};
        int max=arr[0][0];
        for(int i=0;i<arr.length;i++){
            for(int j=0;j<arr[i].length;j++){
                if(arr[i][j]>max){
                    max=arr[i][j];
                }
            }
        }
        System.out.println("数组的最大值为"+max);
    }
}