# HackerRank Solutions – 30 Days of Code – Day 9

Objective
Today, we’re learning and practicing an algorithmic concept called Recursion. Check out the Tutorial tab for learning materials and an instructional video!

Recursive Method for Calculating Factorial

factorial=n*(factorial(n-1))

Write a factorial function that takes a positive integer,N  as a parameter and prints the result of N  ( factorial).

Note: If you fail to use recursion or fail to name your recursive function factorial or Factorial, you will get a score of  0.

Input Format

A single integer,  N (the argument to pass to factorial).

Constraints

• 2<=N<=12
• Your submission must contain a recursive function named factorial.

Output Format

Print a single integer denoting .

Sample Input

3


Sample Output

6

PROGRAM:

#include <stdio.h>

int factorial(int);

int main()
{
int num;
int result;
scanf("%d", &num);
result = factorial(num);
printf("%d",result);
return 0;
}
int factorial(int num)
{
if (num == 0 || num == 1)
{
return 1;
}
else
{
return(num * factorial(num - 1));
}
}

OUTPUT:

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