Write a program to find the factorial of given number using recursion.

Dr. A.P.J. Abdul Kalam Technical University, Lucknow

KCS151 / KCS251 Programming for Problem Solving - Using C Language

Lab Exercises

20. Write a program to find the factorial of the given number using recursion.

/*

 File: Prgrm20.c

 Author: Aditya Saini

 Date: Jan 17, 2021

 Description: Program to find the factorial of the given number using recursion.

*/

#include <stdio.h>

int factorial (int);

int main (void)

{

     int num;

     int fact;

     //Input number

     printf ("Input number: ");

     scanf ("%d", &num);

     //Function call

     fact = factorial (num);

     //Print result

     if (fact > 0)

          printf ("Factorial: %d", fact);

     return 0;

};

int factorial (int num)

{

     //Calculate factorial

     //Base case

     if (num == 1 || num == 0)

          return 1;

     else if (num >= 1)

          //Recursive call

          return num * factorial (num - 1);

     else

     {

          printf ("Error! Negative number");

          return -1;

     }

};

Output

Input number: 7

Factorial: 5040