🔄📚Intermediate

Factorial Using Recursion

Recursive factorial calculation

Recursion is when a function calls itself. Factorial is a classic example:
n! = n × (n-1)! with base case: 0! = 1

Program Code

factorial_recursion.c

1#include <stdio.h>
2
3// Recursive function
4long long factorial(int n) {
5    // Base case
6    if (n == 0 || n == 1) {
7        return 1;
8    }
9    // Recursive case
10    return n * factorial(n - 1);
11}
12
13int main() {
14    int num;
15    
16    printf("Enter a number: ");
17    scanf("%d", &num);
18    
19    if (num < 0) {
20        printf("Factorial not defined for negative numbers\n");
21    } else {
22        printf("%d! = %lld\n", num, factorial(num));
23    }
24    
25    return 0;
26}