C :

#include <stdio.h>
int main()
{
  int year, a, b, c;
  scanf("%d", &year);
  a = year % 4;
  if(a == 0)
  {
    b = year % 100;
    if(b == 0)
    {
      c = year % 400;
      if(c == 0)
        printf("leap year\n");
      else printf("not leap year\n");
    }
    else printf("leap year\n");
  }
  else printf("not leap year\n");
  return 0;
  system("pause");
}

C++ :

#include <iostream>

using namespace std;

int main()
{
    int a;
    cin>>a;
    if(a%100==0)
    {
        if(a%400==0)
        cout<<"leap year"<<endl;
        else
            cout<<"not leap year"<<endl;
    }
    else
    {
        if(a%4==0)
            cout<<"leap year"<<endl;
        else
            cout<<"not leap year"<<endl;
    }

    return 0;
}