In mathematics, the factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n. For example,
6! = 6 x 5 x 4 x 3 x 2 x 1 = 720
The value of 0! is 1, according to the convention for an empty product.
Example Program
/* Program of Factorial Using Recursion in C++
Pardeep Patel @ studywarehouse.com */
#include<iostream>
#include<conio.h>
using namespace std;
//Function
long factorial(int);
int main()
{
// Variable Declaration
int counter, n;
// Get Input Value
cout<<"Enter the Number :";
cin>>n;
// Factorial Function Call
cout<<"Factorial Value of "<<n<" is: "<<factorial(n);
// Wait For Output Screen
getch();
return 0;
}
// Factorial recursion Function
long factorial(int n)
{
if (n == 0)
return 1;
else
return(n * factorial(n-1));
}
Sample Output
Enter the Number :6
Factorial Value of 6 is: 720