Factorial of a number using recursion Dry Run in C

Factorial of a number using recursion is an interactive C dry run visualizer from the Recursion programs section. Study the source code, then use the execution controls to follow each step, variable update, highlighted line, and console output.

This page provides a browser-based dry run with source-code highlighting, auto-scroll, voice narration controls, and execution output for learning the program step by step.

Factorial of a number using recursion Program Code

#include <stdio.h>

// Function to calculate factorial using recursion
long long int factorial(int n)
{
    if (n == 0 || n == 1)   // Base case
        return 1;
    else
        return n * factorial(n - 1);   // Recursive call
}

int main()
{
    int num;
    long long int fact;

    printf("Enter a number: ");
    scanf("%d", &num);

    if (num < 0)
    {
        printf("Factorial is not defined for negative numbers.\n");
    }
    else
    {
        fact = factorial(num);
        printf("Factorial of %d = %lld\n", num, fact);
    }

    return 0;
}

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