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 test;
import java.util.*;
public class Terr {
    public static void main(String[] args) {
        Scanner input =new Scanner(System.in);
        int[]arr=new int [5];
        System.out.println("输入5位整数:");
        int i,j;
        for(i=0;i<5;i++){
            arr[i]=input.nextInt();
        }
        for(i=0;i<arr.length-1;i++){
            for(j=0;j<arr.length-1-i;j++){
                if(arr[j]>arr[j+1]){
                    int temp=arr[j];
                    arr[j]=arr[j+1];
                    arr[j+1]=temp;
                    }
                }
            }
        for(i=0;i<arr.length;i++){
            System.out.println(arr[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 test;
import java.util.*;
public class Terr {
    public static void main(String[] args) {
        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 test;
public class Terr {
    public static void main(String[] args) {
        double arr[][] = { { 1, 2, 3, 4, 5 }, { 6, 7, 8, 9, 10 },
                { 11, 12, 13, 14, 15 }, { 16, 17, 18, 19, 20 } };
         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 test;
public class Terr {
    public static void main(String[] args) {
        int arr[][] = { {2,4,3,55},{6,87,7,9},{56,78,97,56}};
        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);
    }
}