第六周作业

1.定义长度为5的整型数组，输入他们的值，用冒泡排序后输出。

import java.util.Scanner;
public class C {
    public static void main(String[] args) {
          // TODO Auto-generated method stub
        int [] a=new int[5];
        Scanner sc=new Scanner(System.in);
        for(int i=0;i<5;i++) {
            System.out.println("输入第"+(i+1)+"个数：");
            int n=sc.nextInt();
            a[i]=n;
        }
        for(int i=0;i<=a.length-1;i++) {
            for(int j=0;j<a.length-i-1;j++) {
                if(a[j]>a[j+1]) {
                    int max;
                    max=a[j];
                    a[j]=a[j+1];
                    a[j+1]=max;
                }
            }
        }
    for(int b:a) {
        System.out.println(b);
        }
    }
    }

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"

import java.util.Scanner;
public class C {
    public static void main(String[] args) {
          // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        boolean flag= false;
        int[] a = {34,22,35,67,45,66,12,33};
        System.out.println("输入一个数：");
        int b = input.nextInt();
        for (int i = 0; i < a.length; i++) {
            if (a[i] == b) {
                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。

import java.util.Scanner;
public class C {
    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("矩阵形式输出");
                for (int i = 0; i < arr.length; i++) {
                for (int j = 0; j < arr.length - 1; 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.

import java.util.Scanner;
public class C {
    public static void main(String[] args) {
          // TODO Auto-generated method stub
        double[][] a = new double[][]{{1,2,3}, {6,7,8}, {11,12,13}, {16,17,18}};
        double max = 0;
        for (double[] i : a)
        {
            for (double j : i)
            {
                if (j > max)
                {
                    max = j;
                }
            }
        }
        System.out.println("最大值为" + max);
    }
    }