第六周作业

1.定义长度位5的整型数组,输入他们的值,用冒泡排序后输出.

package jxk;
import java.util.Scanner;
public class se {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("数组的值：");
        int[] a = new int[5];
        for(int i=0;i<a.length;i++){
        a[i]=input.nextInt();
       }for(int i=0;i<a.length-1;i++){
           for(int j=0;j<a.length-1-i;j++){
               if(a[j]>a[j+1]){
                   int temp = a[j];
                   a[j] = a[j+1];
                   a[j+1] = temp;
               }
           }
       }System.out.println("冒泡排序后输出：");
       for(int i=0;i<a.length;i++){
           System.out.println(a[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 jxk;
import java.util.Scanner;
public class se {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
         Scanner input = new Scanner(System.in);
         boolean flag= false;
         int[]arr = {34,22,35,67,45,66,12,33};
         System.out.println("请输入一个数：");
         int a = input.nextInt();
         for (int i = 0; i < arr.length; i++) {
             if (arr[i] == a){
                 System.out.println("该数在数组中存在它的下标是：" + i);
                 flag = true;
             }
         }
         if(flag == 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 jxk;

public class Der {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        double arr[][] = { { 4, 23, 9, 15, 58}, { 72, 16, 4, 1, 10 },
                { 31, 25, 13, 44, 66 }, { 86, 57, 18, 19, 29 } };
         for (int i = 0; i < arr.length; i++) {
             for (int j = 0; j < arr[i].length; j++) {
                 System.out.print(arr[i][j] + "	");
             } System.out.println();
         }
    }
}

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 jxk;

public class Der {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int arr[][] = { {23,6,17,4},{6,24,9,1},{17,23,84,95}};
        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("二维数组中最大的是:"+max);
    }
}