题解 | 日期差值

# include<stdio.h>

int isLeapyear(int year){
    if((year%4==0 && year%100!=0) || (year%400==0)){
        return 1;
    }else{
        return 0;
    }
}

int compute_days(int year, int month, int day){
    int days=0;
    int months_day[13] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    for(int i=0; i<year; i++){
        days += (isLeapyear(i)==1) ? 366 : 365;
    }

    for(int i=0; i<month; i++){
        if(i==2){
            days += (isLeapyear(year)==1) ? 29 : months_day[i];
            continue;
        }
            days += months_day[i];
    }

    days += day;

    return days;
}


int main() {
    int year1, month1, day1;
    int year2, month2, day2;
    scanf("%4d%2d%2d", &year1, &month1, &day1);
    scanf("%4d%2d%2d", &year2, &month2, &day2);
    int days1 = compute_days(year1, month1, day1);
    int days2 = compute_days(year2, month2, day2);
    int days = days1>days2 ? days1-days2+1 : days2-days1+1;
    printf("%d\n", days);
    return 0;
}