【C++】判断是否为闰年，是该年的哪一天

//判断是否为闰年，是该年的哪一天#include <iostream>using namespace std;int sum(int month,int day);int leap(int year);int main(){int year,month,day;cout<<"请输入一个日期: ";   cin>>year>>month>>day;int days=sum(month,day);if(leap(year)&&month>2)days++;cout<<year<<"年"<<month<<"月"<<day<<"日是这一年的第"<<days<<"天。\n";if(year%4==0&&year%100!=0||year%400==0)cout<<"该年是闰年";else cout<<"该年不是闰年";}int sum(int month,int day){int day_month[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};for(int i=1;i<month;i++)day+=day_month[i];return day;}int leap(int year){int leap=year%4==0&&year%100!=0||year%400==0;return leap;}