C :

#include<stdio.h>
#define LEAP_YEAR(y)(y)%400==0||(y)%4==0&&(y)%100!=0
int main()
{   
	int year;
	scanf("%d",&year);
	if(year>=1000 && year<=9999)
	{      
		if(LEAP_YEAR(year))	  
		{        
			printf("%d is a leap year.\n", year);
		}      
		else	  
			{      
				printf("%d is not a leap year.\n", year);	  
			}   
	} 
}

C++ :

#include <stdio.h>
#define LEAP_YEAR(y) ((y % 4 == 0 && y % 100 != 0) || (y % 400 == 0))
int main() {
	int year;
	scanf("%d", &year);
	if (LEAP_YEAR(year))
		printf("%d is a leap year.\n", year);
	else
		printf("%d is not a leap year.\n", year);
	return 0;
}

Pascal :

var
  n:longint;
begin
  readln(n);
  if (n mod 4=0) and (n mod 100<>0) or (n mod 400=0) then writeln(n,' is a leap year.')
      else writeln(n,' is not a leap year.');
end.

Java :

import java.util.*;

public class Main{
	public static void main (String[] args) {
		Scanner in=new Scanner(System.in);
		int y=in.nextInt();
		if(y%4==0&&y%100!=0 || y%400==0)
			System.out.println (y+" is a leap year.");
		else
			System.out.println (y+" is not a leap year.");
	}
}