JAVA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 testl;
import java.util.*;
public class Zuoyee {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input=new Scanner(System.in);
        System.out.println("请输入数组的值：");
        int[] arr= new int[5];
        for(int i=0;i<arr.length;i++) {
            arr[i]=input.nextInt();
        }
        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;
             }
          }
        }
        System.out.println("冒号排序为：");
        for (int 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 testl;
import java.util.*;
public class Zuoyee {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
          boolean flag= false;
          int[] b = {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 < b.length; i++) {
           if (b[i] == a) {
            System.out.println("该数的下标是：" + 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 testl;
/*import java.util.**/;
public class Zuoyee {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        double[][] arr = { { 2.3,6.5,7.8,9}, { 5.5,2.9,8.4,5.6 },
                { 41.8,28.6,66,53 }, { 11.6,24.8,2.9,3 },
                { 56,22.3,50.4,25.6 } };
        System.out.println("以矩阵形式输出为");
                for (int i = 0; i < arr.length; i++) {
                for (int j = 0; j < arr.length - 1; j++) {
                System.out.print(arr[i][j] + "\t");
                }
                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 testl;
import java.util.*;
public class Zuoyee {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input=new Scanner(System.in);
        System.out.println("请输入数组的值：");
        int [][] arr=new int[3][4];       
        for(int i=0;i<arr.length;i++) {
            for(int j=0;j<arr[i].length;j++) {
                arr[i][j]=input.nextInt();
            }
        }
        int max=0;
        for(int i=0;i<arr.length;i++) {
            for(int j=0;j<arr[i].length;j++) {
                if(max<arr[i][j]) {
                    max=arr[i][j];
                }
            }
        }
        System.out.println("最大值为"+max);
    }
}