c语言（8.18）

补一下前几天练习的代码

#include<stdio.h>

int main()
{
	int n = 0;
	//scanf("%d", &n);
	
	
	int sum = 0;
	for (int j = 1; j <= 10; j++)
	{
		int mul = 1;//mul应该放在里面才行，每一次新的阶乘mul都是1
		for (int i = 1; i <= j; i++)
		{
			mul = mul * i;
		}
		sum = sum + mul;
	}
	printf("%d\n", sum);


	
	

	

	return 0;
}

#include<stdio.h>
#include<string.h>
#include<windows.h>

int main()
{
	char arr1[] = { "welcome to bit!!!!!!!!" };
	char arr2[] = { "######################" };

	int left = 0;
	int right = strlen(arr1) - 1;
	
	while (left <= right)
	{
		arr2[right] = arr1[right];
		arr2[left] = arr1[left];

		printf("%s\n", arr2);
		Sleep(50);
		left++;
		right--;
	}
	
	

	return 0;
}

#include<stdio.h>
#include<string.h>


int main()
{
	
	char password[20] = { 0 };
	int i = 0;
	for (i = 0; i < 3; i++)
	{
		printf("请输入密码：\n");
		scanf("%s", password);
		
		if (strcmp("123456", password) == 0)
		{
			printf("登录成功");
			break;
		}
		else
		{
			printf("密码错误\n");
		}

	}

	if (i == 3)
	{
		printf("登录失败\n");
	}



	return 0;
}

#include<stdio.h>
#include<stdlib.h>

void menu()
{
	printf("************************\n");
	printf("*******  1.play   ******\n");
	printf("*******  0.exit   ******\n");
	printf("************************\n");
	//故意把exit设计成0的，这样while可以直接退出

}
void game()
{
	//设置随机数
	//srand(time(NULL));不用放在里面，因为放在里面每玩一次游戏，
	//都会重新设计一个随机值，且速度快的话，两个随机数相差不大，甚至相等	
	int a = rand() % 100 + 1;
	//printf("%d\n", a);
	printf("请输入一个数字：\n");
	int guess = 0;
	scanf("%d", &guess);
	if (guess > a)
	{
		printf("猜大了\n");
	}
	else if (guess < a)
	{
		printf("猜小了\n");
	}
	else
	{
		printf("恭喜你，猜对了\n");
	}
}
int main()
{
	srand(time(NULL));
	int input = 0;
	do
	{
		menu();
		printf("请选择：\n");
		scanf("%d", &input);
		switch (input)
		{
			case 1:
				game();
				break;
			case 0:
				printf("退出游戏\n");
				break;
			default:
				printf("输入错误，请重新选择\n");
				break;
		}

	} while (input);

	return 0;
}