第六周JAVA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.

import java.util.*;

public class jkk {
    public static void main(String[] args) {
        int[] a = { 3, 9, 8, 6, 4 };
        int temp = 0;
        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]) {
                    temp = a[j + 1];
                    a[j + 1] = a[j];
                    a[j] = temp;
                }
            }
        }
        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"

import java.util.*;

public class jkk {
    public static void main(String[] args) {
        int[] arr = { 34, 22, 35, 67, 45, 66, 12, 33 };
        Scanner input = new Scanner(System.in);

        System.out.print("请输入一个数字:");

        int n = input.nextInt();
        for (int i = 0; i < arr.length; i++) {
            if (n == arr[i]) {
                System.out.println(i);
                break;
            } else {
                System.out.println("not found");
                break;
            }
        }

    }

}

 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.*;

public class jkk {
    public static void main(String[] args) {
        double[][] a = { { 4.6, 5.3, 7.6, 5.9, 12.0 }, { 1.9, 6.5, 5.9, 86.6, 4.8 }, { 8.85, 41.2, 12.3, 5.3, 1.11 },
                { 4.9, 8.9, 7.9, 39.4, 57.8 } };
        for (int i = 0; i < a.length; i++) {
            for (int j = 0; j < 5; j++) {
                System.out.print(a[i][j] + "	");
            }
            System.out.print("
");
        }
    }

}

 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.*;

public class jkk {
    public static void main(String[] args) {
        int arr[][] = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 }, { 10, 11, 12 } };
        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);
    }
}