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.

public class work {
     public static void main(String[] args) {
         int[] arr={1,5,2,7,6};
         for(int i=0;i<arr.length-1;i++){
             for(int 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(int i=0;i<arr.length;i++){
             System.out.print(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"

import java.util.*;
public class work {
     public static void main(String[] args) {
         Scanner a = new Scanner(System.in);
            int[] b = { 34, 22, 35, 67, 45, 66, 12, 33 };
            int k = -1;
            System.out.println("输入一个数");
            int c = a.nextInt();
            for (int i = 0; i < b.length; i++) {
                if (b[i] == c) {
                    k = i;
                    System.out.println("下标为" + i);
                    break;
                }
            }
            if (k == -1) {
                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。

public class work {
     public static void main(String[] args) {
         double[][] a = {{1.1,2.2,3.3,4.4},{5.5,6.6,7.7,8.8},{10.1,10.2,10.3,10.4},{11.1,11.2,11.3,11.4},{12.1,12.2,12.3,12.4}};
            for(int i = 0;i < 5;i++) {
                for(int j = 0;j < 4;j++) {
                    System.out.print(a[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.

public class work {
     public static void main(String[] args) {
         int arr[][] = { {1,2,3}, { 5,6,8}, {11,15,17}, {16,19,21} };
         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("该二维数组的最大值为："+max);  
     }
 }