1229. 日期问题

https://www.acwing.com/problem/content/description/1231/

蒟蒻只会暴力
而Y总的思路就特牛,直接从日起开始枚举,只需判断日期是否合法即可输出

#include <cstdio>
#include <iostream>

using namespace std;

int days[13] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

bool check_valid(int year, int month, int day)//判断日期是否合法
{
	if (month == 0 || month > 12) return false;
	if (day == 0) return false;
	if (month != 2)
	{
		if (day > days[month]) return false;
	}
	else
	{
		int leap = ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0));
		if (day > days[month] + leap) return false;
	}
	
	return true;
}
int main()
{
	int a, b, c;
	scanf("%d/%d/%d", &a, &b, &c);//格式输入
	for (int date = 19600101; date <= 20591231; date ++ )
	{
		int year = date / 10000, month = date % 10000 / 100, day = date % 100;
		if (check_valid(year, month, day))
		{
			if ((year % 100 == a && month == b && day == c) ||  // 年/月/日
				(month == a && day == b && year % 100 == c) ||  // 月/日/年
				(day == a && month == b && year % 100 == c) )   //月/日/年
				printf("%d-%02d-%02d\n", year, month, day);  //补前导0
		}
	}
	return 0;
}