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 lucky;

import java.util.Scanner;
public class happy {

	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 lucky;

import java.util.Scanner;
public class happy {

	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 lucky;

import java.util.Scanner;
public class happy {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		      double [][] a = {{31,63,86,99},{32,54,78,10},
		              {11,12,13,14},{16,17,18,19},
		              {22,44,66,88}};
		      for(int i=0;i<a.length;i++){
		          System.out.println();
		          for(int j=0;j<a.length-1;j++){
		              System.out.print(a[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 lucky;

import java.util.Scanner;
public class happy {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		    int a[][] = {{22,34,55},{88,10,31},
		            {77,64,27},{61,52,23}};
		    int max = a[0][0];
		    for(int i=0;i<a.length;i++){
		        for(int j=0;j<a[i].length;j++){
		            if(a[i][j]>max){
		                max = a[i][j];
		            }
		        }
		    }
		 System.out.println("该二维数组的最大值为:"+max);
	 }
}