一个用java代码实现的猜数字游戏

import java.util.Random;

import java.util.Scanner;

public class Test {

public static int sum (int n) {

if (n == 0) {

return 0;

}

return n + sum(n - 1);

}

public static void main(String[] args) {

System.out.println(sum(10));

}

public static void main3(String[] args) {

Random random = new Random();

int randNum = random.nextInt(100);

System.out.println(randNum);

Scanner scan = new Scanner(System.in);

while (true) {

System.out.println("请输入你要猜的数字");

int num = scan.nextInt();

if (num < randNum) {

System.out.println("小了");

} else if (num == randNum) {

System.out.println("等于");

break;

} else {

System.out.println("大了");

}

}

}

public static void main2(String[] args) {

double sum = 0;

int flg = 1;

for (int i = 1; i <= 100; i++) {

sum = sum + 1.0 / i * flg;

flg = -flg;

}

System.out.println(sum);

}

public static void main1(String[] args) {

int count = 0;

for (int i = 1; i <= 100; i++) {

if (i % 10 == 9) {

count++;

}

if (i / 10 == 9) {

count++;

}

}

System.out.println(count);

}

}