第六周上机作业

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 as;

import java.util.Scanner;
public class unll {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        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.print(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 as;

import java.util.Scanner;
public class unll {
    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 as;

import java.util.Scanner;
public class unll {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        double[][] arr = { { 1,2,3,4 }, { 5,6,7,8 },{ 9,10,11,12 },
                { 13,14,15,16}, { 17,18,19,20  } };
        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < arr[i].length; j++) {
                System.out.print(arr[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.

package as;

import java.util.Scanner;
public class unll {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int arr[][] = { { 1,2,10}, { 15,5,7 }, {3,9,6 }, {14,17,21 } };
        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：" + max);
    }
}