题解 | #日期差值#

#include <iostream>
#include <cstdio>

using namespace std;

int daytable[2][13]={
    {31,28,31,30,31,30,31,31,30,31,30,31},
    {31,29,31,30,31,30,31,31,30,31,30,31}
};

bool IsLeapYear(int year){      //判断是否是闰年
    return  (year%4==0 && year%100!=0) || (year%400==0);     //如果是闰年返回1,否则返回0
}

int NumberOfYear(int year){
    if(IsLeapYear(year)){
        return 366;
    }else{
        return 365;
    }
}

//获取年份
int getyear(int num){
    return num/10000;
}
//获取月份
int getmonth(int num){
    return (num%10000)/100;
}
//获取日期
int getday(int num){
    return (num%10000)%100;
}

int main(){
    int num1,num2;
    while(cin>>num1>>num2){
        if (num1>num2)  swap(num1,num2);    //始终保持较小的为num1较大的为num2
        int year1,year2,month1,month2,day1,day2;
        year1=getyear(num1);
        year2=getyear(num2);
        month1=getmonth(num1);
        month2=getmonth(num2);
        day1=getday(num1);
        day2=getday(num2);

        int row=IsLeapYear(year1);
        int days1=0; //num1对应的是当年第几天
        for(int j=0;j<month1-1;j++){
            days1+=daytable[row][j];
        }
        days1+=day1;
//        cout<<days1<<endl;
        row=IsLeapYear(year2);
        int days2=0; //num2对应的是当年第几天
        for(int j=0;j<month2-1;j++){
            days2+=daytable[row][j];
        }
        days2+=day2;
//        cout<<days2<<endl;
        int finalday=0;
        for(int i=year1;i<year2;i++){
            finalday+=NumberOfYear(i);
//            cout<<finalday<<endl;
        }
        finalday+=(days2-days1+1);
//        cout<<year1<<' '<<year2<<endl;
//        cout<<month1<<' '<<month2<<endl;
//        cout<<day1<<' '<<day2<<endl;
        cout<<finalday<<endl;
    }
    return 0;
}