题解 | 日期差值

#include<iostream>
#include<algorithm>
#include<string>
using namespace std;
void nextday(int& y, int& m, int& d) {
	int dayMonth[] = { 0,31,28,31,30,31,30,31,31,30,31,30,31 };
	bool isLeap = y % 400 == 0 || y % 4 == 0 && y % 100 != 0;
	if (isLeap) {
		dayMonth[2] = 29;
	}
	else {
		dayMonth[2] = 28;
	}
	d++;
	if (d > dayMonth[m]) {
		m++;
		d = 1;
	}
	if (m > 12) {
		m = 1;
		y++;
	}
}
int main() {
	int date1, date2;
	while (cin >> date1 >> date2) {
		//这里有点问题，题目中没说那个日期在前哪个日期在后，所以要先加一个判断，让date1是小日期，date2是大日期
		if (date1 > date2) {
			swap(date1, date2);
		}
		int day = date1 % 100;
		date1 /= 100;
		int month = date1 % 100;
		int year = date1 / 100;
		int res = 1;
		while (year * 10000 + month * 100 + day != date2) {
			nextday(year, month, day);
			res++;
		}
		cout << res << endl;
	}
	return 0;
}