4.10

//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;

public class day06 {
    public static void main(String[] args) {
        int[] a = new int[] { 1, 3, 2, 5, 8 };
        int t;
        for (int i = 0; i < a.length-1; i++) {
            for (int j = 0; j < a.length-1-i;j++) {
                if (a[j + 1] > a[j]) {
                    t = a[j];
                    a[j] = a[j + 1];
                    a[j + 1] = t;
                }
            }
        }
        for (int j = 0; j < a.length; j++) {
            System.out.print(a[j] + ", ");
        }
    }
}

//2定义数组{34,22,35,67 ,45,66,12,33}输入-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.*;

public class day06 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int[] n = new int[] { 34, 22, 35, 67, 45, 66, 12, 33 };
        System.out.println("输入一个数");
        int a = input.nextInt();
        int f=0,i,t=0;
        for (i = 0; i < n.length; i++) {
            if (a == n[i]){
                f=1;
                t=i;
                }
        }
        if(f==1){
            System.out.println("存在，下标为:" + t);
            }
        else{
            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;



public class day06 {
    public static void main(String[] args) {
        double[][] a=new double[5][4];
        for(int i=0;i<5;i++){
            for(int j=0;j<4;j++){
                System.out.print(a[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 day06 {
    public static void main(String[] args) {
    
        int[][] a={{1,2,3},{4,5,6},{7,8,9},{10,11,12}};
        int t=a[0][0];
        for(int i=0;i<4;i++){
            for(int j=0;j<3;j++){
                if(a[i][j]>t){
                    t=a[i][j];
                }
            }
        }
        System.out.println("最大为："+t);
    }
}