题解 | 日期差值

#include <stdio.h>
using namespace std;
int Nextday(int year){
    int year1=year/10000;
    int month=(year/100)%100;
    int day=year%100;
    int arr[]={ 0,31,28,31,30,31,30,31,31,30,31,30,31 };
    int isLeap=year1%400==0||year1%4==0&&year1%100!=0;
    if(isLeap){
        arr[2]=29;
    }else{
        arr[2]=28;
    }
    ++day;
    if(day>arr[month]){
        ++month;
        day=1;
    }
    if(month>12){
        ++year1;
        month=1;
    }
    return year1*10000+month*100+day;
}
int main(){
    int year1,year2;
    scanf("%d\n",&year1);
    scanf("%d",&year2);
        int allday=1;
        if(year1+1==year2){
            allday=2;
            printf("%d\n",allday);
        }
        else{
            int nextday=Nextday(year1);
            while(nextday!=year2){
                ++allday;
                nextday=Nextday(nextday);
            }
            printf("%d\n",allday+1);
        }

    return 0;
}