作业。

1.

package week;

 

import java.util.Scanner;

 

public class zy {

 

    public static void main(String[] args) {

        // TODO Auto-generated method stub

        int[] num = new int[5];

        Scanner input = new Scanner(System.in);

        for (int i = 0; i < num.length; i++) {

            System.out.print("请输入第" + (i + 1) + "个数:");

            num[i] = input.nextInt();

        }

        for (int i = 0; i < num.length - 1; i++) {

            for (int j = 0; j < num.length - 1 - i; j++) {

                if (num[j] > num[j + 1]) {

                    int temp = num[j];

                    num[j] = num[j + 1];

                    num[j + 1] = temp;

                }

            }

        }

        for (int i = 0; i < num.length; i++) {

            System.out.print(num[i] + " ");

        }

 

    }

 

}

2.

package week;

import java.util.Scanner;

public class zy {

    public static void main(String[] args) {
         //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"
        int[] arr = {34,22,35,67,45,66,12,33};
        int j=0;
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入一个数");
        int a = sc.nextInt();
        for(int i = 0;i<arr.length;i++) {
            if(a==arr[i]) {
                j=1;
                int xiabiao = i;
                System.out.println("下标为："+xiabiao);
                break;
            }
        }if(j==0) {
            System.out.println("no found");
        }
    }

}

3.

package week;
public class zy {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        double[][] a = { { 1.1, 3.2, 5.3, 7.4 }, { 9.1, 11,2, 13.3, 15.4 },
                { 17.1, 19.2, 21.3, 23.4 }, { 25.1, 27.2, 29.3, 31.4 },
                { 33, 35, 37, 39 } };
                for (int i = 0; i < a.length; i++) {
                for (int j = 0; j < a.length - 1; j++) {
                System.out.print(arr[i][j] + " ");
                }
                System.out.println(" ");
            }
        }        
    }

 

4.

package week;

public class zy{

    public static void main(String[] args) {
        //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.
        int[][] arr = {{10,21,31,14},{15,26,38,47},{18,24,83,46}};
        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(max);
    }

}