题解 | #日期差值#

#include<stdio.h>
int months[13] ={0,31,28,31,30,31,30,31,31,30,31,30,31};

bool IsRun(int year){
    if(year%100!=0&&year%4==0) return true;
    if(year%400==0) return true;
    else
        return false;
}
void NextDay(int &year,int &month,int &day){
    int maxday = months[month];
    if(IsRun(year)&&month==2) maxday = 29;
    if(day == maxday){
        if(month==12){ year++; month = 1;day = 1; }
        else {month++; day = 1;}
    }else {
        day++;
    }
}
int main(){
    int year0,month0,day0;
    int year1,month1,day1;
    int count = 1;
    scanf("%4d%2d%2d",&year0,&month0,&day0);
    scanf("%4d%2d%2d",&year1,&month1,&day1);
    while(year0!=year1||month0!=month1||day0!=day1){
        NextDay(year0,month0,day0);
        count ++;
    }

    printf("%d",count);
}