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 homework;

import java.util.Scanner;

public class homework1 {

    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 homework;

import java.util.Scanner;

public class homework2 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
    Scanner sc = new Scanner(System.in);
    boolean flag = false;
    int[] x = new int[]{34,22,35,67,45,66,12,33};
    System.out.print("请输出一个数：");
    int a = sc.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);
            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 homework;

public class homework3 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
      double [][] arr = {{1,3,5,7},{9,11,13,15},
              {17,19,21,23},{25,27,29,31},
              {33,35,37,39}};
      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 homework;

public class homework4 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
    int arr[][] = {{2,4,6},{8,10,12},
            {14,16,18},{20,22,24}};
    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);
    }
}