C PROGRAMMING PROGRAM • DECISION MAKING

Check Whether a Year Is a Leap Year

Learn how to check whether a year is a leap year using a clear C program.

BeginnerNested conditionsLogical operatorsCalendar

PROBLEM UNDERSTANDING

Input and expected output

Sample input

Sample output

2024 is a leap year.

COMPLETE C PROGRAM

Complete C implementation

#include <stdio.h>

int main(void)
{
    int year;

    printf("Enter a year: ");
    scanf("%d", &year);
    if (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0))
        printf("%d is a leap year.\n", year);
    else
        printf("%d is not a leap year.\n", year);
    return 0;
}

CURRENT STEP

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SELECTED LINE

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EXPECTED OUTPUT FOR THE SAMPLE

2024 is a leap year.

0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

Read the required input values.
A leap year is divisible by 400, or divisible by 4 but not by 100.
Display the computed result.

A leap year is divisible by 400, or divisible by 4 but not by 100.

EFFICIENCY

Time and space complexity

Time complexity

O(1)

Auxiliary space

O(1)

DEBUGGING CHECKLIST

Common mistakes

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Use the correct format specifier for every variable.

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Initialize variables before using their values.

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Check braces, semicolons and input order carefully.

Try it yourself

Practice: Run the program with the sample input, predict its output, and then test one boundary case of your own.