题解 | #日期差值#

#include <climits>
#include <iostream>
using namespace std;

class Date {
  public:
    Date(int year, int month, int day) {
        _year = year;
        _month = month;
        _day = day;
    }
    int Days(int y, int m) {
        int arr[13] = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
        if (m == 2 )
            if (y % 4 == 0 && y % 100 != 0 || y % 400 == 0)
                return 29;
        return arr[m];
    }
    bool operator==(Date d) {
        if (this->_year == d._year && this->_month == d._month && this->_day == d._day)
            return true;
        return false;
    }
    Date operator+(int n) {
        Date tmp = *this;

        tmp._day += n;
        while (tmp._day > Days(tmp._year, tmp._month)) {
            tmp._day -= Days(tmp._year, tmp._month);
            tmp._month++;
        }
        while (tmp._month > 12) {
            tmp._month -= 12;
            tmp._year++;
        }
        return tmp;
    }

    Date& operator++() {
        *this = *this + 1;
        return *this;
    }
    bool operator>(Date d) {
        if (this->_year > d._year)
            return true;
        else if (this->_year == d._year && this->_month > d._month)
            return true;
        else if (this->_year == d._year && this->_month == d._month &&
                 this->_day > d._day)
            return true;
        else
            return false;
    }
    bool operator<(Date d) {
        if (*this > d || *this == d) return false;
        return true;
    }
    int operator-(const Date d) {
        if (*this < d) {
            //
            Date tmp = *this;
            int n = 0;
            while (!(tmp == d)) {
                ++tmp;
                n++;
            }
            return n;
        }
        Date tmp = d;
        int n = 0;
        while (!(tmp == *this)) {
            ++tmp;
            n++;
        }
        return n;
    }
  private:
    int _year;
    int _month;
    int _day;
};

int main() {
    char ch1[9];
    char ch2[9];

    while (cin >> ch1 >> ch2) { // 注意 while 处理多个 case
        int year1, year2, month1, month2, day1, day2;
        sscanf(ch1, "%4d%2d%2d", &year1, &month1, &day1);
        sscanf(ch2, "%4d%2d%2d", &year2, &month2, &day2);
        Date d1(year1,month1,day1);
        Date d2(year2,month2,day2);
        int ret = d2-d1+1;
        cout << ret << endl;
    }
}
// 64 位输出请用 printf("%lld")