题目链接 

思路很简单：判断前面的那一天到1970年的天数取模7和当前的是否相同

坑点：如果是2月的29日，需要判断当前年是否是闰年

谨以此文纪念今天沙雕的我

To be one!

#include <bits/stdc++.h>
using namespace std;
int getDaysFrom1970(int year, int month, int day){
	int days = 0;
	for (int i = 1970; i < year; i++){
		if(i % 4 == 0 && i % 100 != 0 || i % 400 == 0)days += 366;
		else days += 365;
	}
	switch (month - 1){
		case 11 : days += 30;
		case 10 : days += 31;
		case 9 : days += 30;
		case 8 : days += 31;
		case 7 : days += 31;
		case 6 : days += 30;
		case 5 : days += 31;
		case 4 : days += 30;
		case 3 : days += 31;
		case 2 : if(year % 4 == 0 && year % 100 || year % 400 == 0)days += 29;else days += 28;
		case 1 : days += 31;
	}
	days += day;
	return days;
}
int main()
{
	int year, month, day;
	while (~scanf("%d %d %d", &year, &month, &day)){
		int days = getDaysFrom1970(year, month, day);
		int moded = days % 7;
		int sum;
		int res;
		for (int i = year + 1; ; i++){
			sum = getDaysFrom1970(i, month, day);
			if(month == 2 && day == 29){
				if(sum % 7 == moded && i % 4 == 0 && i % 100 != 0 || i % 400 == 0){
					res = i;
					break;
				}
			}
			else if(sum % 7 == moded){
				res = i;
				break;
			}
		}
		printf("%04d\n", res);
	}
	return 0;
}