Program To Find Factorial Of Number In C Language
This program calculates the factorial of a given number using recursion. The factorial() function is a recursive function that multiplies the number with the factorial of the number one less than itself until it reaches 1 or 0 (base case). The program prompts the user to input a number, and then it calculates and displays its factorial. If the user enters a negative number, the program informs that the factorial is not defined for negative numbers.
#include <stdio.h>
// Function to calculate the factorial of a number
unsigned long long factorial(int num) {
if (num == 0 || num == 1) {
return 1;
} else {
return num * factorial(num - 1);
}
}
int main() {
int number;
printf("Enter a number to find its factorial: ");
scanf("%d", &number);
if (number < 0) {
printf("Factorial is not defined for negative numbers.\n");
} else {
unsigned long long result = factorial(number);
printf("Factorial of %d is %llu.\n", number, result);
}
return 0;
}
Output
Enter a number to find its factorial: 5 Factorial of 5 is 120.
