Write a C Program to Check Leap Year.

A leap year, in the Gregorian calendar, is a year that is evenly divisible by 4, except for century years (years ending with 00), which must be divisible by 400 to be considered a leap year. The concept of a leap year is important for ensuring that our calendar remains synchronized with the Earth's revolutions around the Sun. In this article, we will guide you through the process of writing a C program to check whether a given year is a leap year or not, without using structures and functions.

The Logic Behind Leap Years

Before delving into the C program itself, let's understand the logic behind determining leap years: 

1. If a year is divisible by 4 and not divisible by 100, it is a leap year.
2. If a year is divisible by 100 and also divisible by 400, it is a leap year.

Here's a  C Program to Check Leap Year:

#include<stdio.h>
#include<conio.h>
void main()
{
     int year; // Taking input from the user
     printf("Enter a year: ");
     scanf("%d", &year);

     // Checking if it's a leap year
     if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0))
     {
         printf("%d is a leap year.\n", year);
     }
     else
     {
         printf("%d is not a leap year.\n", year);
     }
}

• We declare an integer variable year to store the input year.
• The user is prompted to enter a year, and their input is stored in the year variable.
• The program then checks the conditions for a leap year:
• (year % 4 == 0 && year % 100 != 0) checks if the year is divisible by 4 but not divisible by 100.
• (year % 400 == 0) checks if the year is divisible by 400.
• If either of the conditions is satisfied, the program prints that the input year is a leap year; otherwise, it prints that the year is not a leap year

Output: