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 pro1;
import java.util.*;
public class test {
    public static void main(String[] args) {
         int[] a = new int[5];
            int i, j;
            int k;
            Scanner input = new Scanner(System.in);
            System.out.println("请输入5个整数:");
            for (i = 0; i < 5; i++) {
                a[i] = input.nextInt();
            }
            for (i = 0; i < a.length - 1; i++) {
                for (j = 0; j < a.length - 1 - i; j++) {
                    if (a[j] > a[j + 1]) {
                        k = a[j];
                        a[j] = a[j + 1];
                        a[j + 1] = k;
                    }
                }
            }
            System.out.println("冒泡排序:");
            for (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 pro1;
import java.util.*;
public class test {
    public static void main(String[] args) {
        Scanner a = new Scanner(System.in);
        int[] b = { 34, 22, 35, 67, 45, 66, 12, 33 };
        int k = -1;
        System.out.println("输入一个数");
        int c = a.nextInt();
        for (int i = 0; i < b.length; i++) {
            if (b[i] == c) {
                k = i;
                System.out.println("下标为" + i);
                break;
            }
        }
        if (k == -1) {
            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 pro1;
import java.util.*;
public class test {
    public static void main(String[] args) {
        double[][] a = {{1.1,2.2,3.2,4.4},{6.6,7.7,8.8,9.9},{12.1,13.5,14.5,15.5},{16.5,17.8,18,19.4},{11.2,12.2,13.3,14.4}};
        for(int i = 0;i < 5;i++) {
            for(int k = 0;k < 4;k++) {
                System.out.print(a[i][k]+"   ");         
            }
            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 pro1;
import java.util.*;
public class test {
    public static void main(String[] args) {
         double[][] a = {{1.1,2.2,3.2,4.4},{6.6,7.7,8.8,9.9},{12.1,13.5,14.5,15.5}};
            double max = a[0][0];
            for(int i=0;i<3;i++) {
                for(int j=0;j<4;j++) {
                    if(max < a[i][j]) {
                        double b ;
                        b = max;
                        max = a[i][j];                   
                }
            }
        }System.out.println("最大值为："+max);
    }
}