C :

#include<stdio.h>
int main()
{
    int n,y,r,i,s,N;
    while(~scanf("%d%d%d",&n,&y,&r))
    {
        s=0;
    if((n%4==0&&n%100!=0)||(n%4==0&&n%400==0))
    {
        for(i=1;i<=y-1;i++)
        {
            if(i==1||i==3||i==5||i==7||i==8||i==10||i==12)   s+=31;
            else
                if(i==2)   s+=29;
            else           s+=30;

        }
        s+=r;
    }
    else
    {
                for(i=1;i<=y-1;i++)
        {
            if(i==1||i==3||i==5||i==7||i==8||i==10||i==12)   s+=31;
            else
                if(i==2)   s+=28;
            else           s+=30;

        }
        s+=r;
    }
    printf("%d\n",s);
    }
    return 0;
}

C++ :

#include <cstdio>
#include <iostream>
using namespace std ;
int run[] = {31,29,31,30,31,30,31,31,30,31,30,31} ;
int ping[] = {31,28,31,30,31,30,31,31,30,31,30,31} ;
int isRun(int year)
{
    if(year%400==0 || (year%4==0 && year%100!=0))
        return 1 ;
    else return 0 ;
}

int main()
{
    int year,month,day ;
    while(scanf("%d%d%d",&year,&month,&day)!=EOF)
    {
        int cnt = 0 ;
        if(isRun(year))
        {
            for(int i = 0 ; i<month-1 ;i++)
                cnt+=run[i] ;
            cnt+=day ;
        }
        else
        {
            for(int i = 0 ; i<month-1 ;i++)
                cnt+=ping[i] ;
            cnt+=day ;
        }
        printf("%d\n",cnt) ;
    }

}