清理缓存区

int main()
{
	int rat = 0;
	char password[20] = { 0 };
	printf("输入密码：");
	scanf("%s", password);
	while ((rat = getchar()) != '\n')
	{
		;
	}
	printf("请确认输入（y/n）:");
	rat = getchar();
	if (rat == 'y')
	{
		printf("correct\n");
	}
	else
	{
		printf("error\n");
	}
	return 0;
}