Write factorial function & use the function to find the sum of series S = 1! + 2! +...n!

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

KCS151 / KCS251 Programming for Problem Solving - Using C Language

Lab Exercises

19. Write factorial function & use the function to find the sum of series S = 1! + 2! +...n!

/*

 File: Prgrm19.c

 Author: Aditya Saini

 Date: Jan 17, 2021

 Description: Program to find the sum of series S = 1! + 2! +...n!

*/

#include <stdio.h>

int factorial (int);

int main (void)

{

     int terms;

     int sum;

     int i;

     //Input number of terms

     printf ("Input number of terms: ");

     scanf ("%d", &terms);

     //Calculate sum of series

     sum = 0;

     for (i = 1; i <= terms; i++)

          sum = sum + factorial (i);

     //Print result

     printf ("Sum of Series (S = 1! + 2! ... + %d!): %d", terms, sum);

     return 0;

};

int factorial (int num)

{

     int fact;

     int i;

     //Calculate factorial

     fact = 1;

     for (i = 1; i <= num; i++)

          fact = fact * i;

     //Return factorial

     return fact;

};

Output

Input number of terms: 5

Sum of Series (S = 1! + 2! ... + 5!): 153