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 qin;
import java.util.Scanner;
public class ling {
    public static void main(String[] args) {
        Scanner input=new Scanner(System.in);
        System.out.println("输入数组的值：");
        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 t=a[j];
                   a[j]= a[j+1];
                   a[j+1] = t;
                }
             }
           }
           System.out.println("冒号排序为：");
           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 qin;
import java.util.Scanner;
public class ling {
    public static void main(String[] args) {
        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 qin;
import java.util.Scanner;
public class ling{
    public static void main(String[] args) {
         double[][] a = { { 1.3,2.3,4.5,1.7,5.6 }, { 2.3,4.2,3.5,7.5,6.7 },
                    { 1.1,9.7,6.8,6.6,5.9 }, { 2.8,34.5,78.6,56.4,33.5 },
                    { 45.4,66.6,77.7,88.8,99.9 } };
                    for (int i = 0; i < a.length; i++) {
                    for (int j = 0; j < a.length - 1; j++) {
                    System.out.print(a[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 qin;
import java.util.Scanner;
public class ling{
    public static void main(String[] args) {
         Scanner input=new Scanner(System.in);
         System.out.println("请输入数组的值：");
         int [][] b=new int[3][4];    
         for(int i=0;i<b.length;i++) {
              for(int j=0;j<b[i].length;j++) {
               b[i][j]=input.nextInt();
              }
             }
         int max=0;
         for(int i=0;i<b.length;i++) {
          for(int j=0;j<b[i].length;j++) {
           if(max<b[i][j]) {
            max=b[i][j];
           }
          }
         }
         System.out.println("最大值为"+max);
        }
}