JAVA练习2

猜数字游戏

import java.util.Random;
import java.util.Scanner;;
class diyici {public static void main(String[] args) {
        Random random = new Random(); /
        Scanner sc = new Scanner(System.in);
        int toGuess = random.nextInt(100);
       while (true) {
            System.out.println("请输入要输入的数字: (1-100)");
            int num = sc.nextInt();
            if (num < toGuess) {
                System.out.println("低了");
            } else if (num > toGuess) {
                System.out.println("高了");
            } else {
                System.out.println("猜对了");
                break;
            }
        }
        sc.close();
    }
}

水仙花数

class diyici {
    public static void main(String[] args) {
        int i;
        for (i = 100; i < 1000; i++) {
            int m = i % 10;
            int k = i / 10 % 10;
            int n = i / 100;
            if (i == m * m * m + n * n * n + k * k * k) {
                System.out.println(i);
            }
        }
    }
}

计算分数的值

public class diyici{
    public static void main(String[] args){
        double n=0.0;
        double i=-1.0;
        double m=0.0;
        double sum=0.0;
        for(n=1;n<101;n++){
            i=-i;
            m=(1/n)*i;
            sum=sum+m;
        }
        System.out.println(sum);
    }
}

最大公约数

import java.util.Scanner;
public class diyici{
    public static void main(String[] args){
        Scanner s = new Scanner(System.in);
        System.out.print("请输入第一个数：");
        int m = s.nextInt();
        Scanner sc = new Scanner(System.in);
        System.out.print("请输入第二个数：");
        int n = sc.nextInt();
        if(m>n){
            int tmp = m;
            m=n;
            n=tmp;
        }
        int sum=m;
        for(;sum>0;sum--){
            if(m%sum==0&&n%sum==0){
                System.out.println(sum);
                break;
            }
        }
    }
}

二进制1的个数

import java.util.Scanner;
public class diyici {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        System.out.print("请输入第一个数：");
        int m = s.nextInt();
        int count = 0;
        while (m != 0) {
            if ((m & 1) == 1) {
                count++;
            }
            m = m >>> 1;
        }
        System.out.println(count);
    }
}

二进制序列

获取一个数二进制序列中所有的偶数位和奇数位， 分别输出二进制序列

import java.util.Scanner;
public class diyici{
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        System.out.println("输入一个数");
        int num=sc.nextInt();
        System.out.println("奇数位");
        for(int i=30;i>=0;i-=2){
            System.out.print((num>>i)&1);
        }
        System.out.println();
        System.out.println("偶数位");
        for(int i=31;i>0;i-=2){
            System.out.print((num>>i)&1);
        }
    }
}

模拟登陆

编写代码模拟三次密码输入的场景。 最多能输入三次密码，密码正确，提示“登录成功”,密码错误， 可以重新输 入，最多输入三次。三次均错，则提示退出程序

import java.util.Scanner;
public class diyici {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);

        int i = 3;
        while (i != 0) {
            System.out.println("请输入密码： ");
            String mima = s.nextLine();
            if ("leyty123".equals(mima)) {
                System.out.println("登录成功");
                break;
            } else {
                System.out.println("密码错误，请重新输入： ");
                i--;
                System.out.println("你还有" + i + "次机会");
            }
        }
    }
}

##输出一个整数的每一位

import java.util.Scanner;
public class diyici {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);

        int i = 3;
        while (i != 0) {
            System.out.println("请输入密码： ");
            String mima = s.nextLine();
            if ("leyty123".equals(mima)) {
                System.out.println("登录成功");
                break;
            } else {
                System.out.println("密码错误，请重新输入： ");
                i--;
                System.out.println("你还有" + i + "次机会");
            }
        }
    }
}

输出乘法口诀表

import java.util.Scanner;
public class diyici {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("输入一个数");
        int n = sc.nextInt();
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j < i; j++) {
                int sum = i * j;
                System.out.print(j + "*" + i + "*" + sum);
            }
            System.out.println();
        }
    }
}