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 learn;
import java.util.Arrays;
public class learn1 {

    public static void main(String[] args) {
        // TODO Auto-generated method study
                int[] aa = {1,6,2,3,9};
                //冒泡排序
                for(int i=0; i<aa.length-1; i++) {  
                    for(int y=0; y<aa.length-i-1; y++) {  
                        if(aa[y]>aa[y+1]) {
                            int temp = aa[y];
                            aa[y] = aa[y+1];
                            aa[y+1] = temp;
                        }
                    }
                }
                for(int element : aa) {
                    System.out.print(element+" ");
                }
            }
}

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 learn;
import java.util.Scanner;
public class learn1 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int[] arr= { 34, 22, 35, 67, 45, 66, 12, 33 };
        Scanner sc = new Scanner(System.in);
        System.out.println("输入数字，查找它是否在数组中");
        int x = sc.nextInt();
        int y = 0;
        for (int i = 0; i < arr.length; i++) {
            if (x == arr[i]) {
                System.out.println("下标为：" + i);
                y=1;
                }
            }
        if (y == 0) {
        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 learn;
import java.util.Scanner;
public class learn1 {
    public static void main(String[] args){
        double[][] arr = { { 1,2,3,4 }, { 5,4,2,1 },
                { 6,7,8,9 }, { 9,10,13,12}, { 14,15,16,17  } };
        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 learn;
public class learn1 {
    public static void main(String[] args){
        int arr[][] = { { 0,9,8 }, { 7,6,5 }, { 4,3,2 }, { 2,12,1 } };
        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);
            }
}