C++ Program to find factorial

Here we will see how to write a program to find the factorial of a given number.

Basically we find factorial of any number by using its formula. For example 5!=5*4*3*2*1=120.
To write the program we have to follow some steps. So lets see the Algorithm first

Algorithm:

Step 1: Start.

Step 2: Read num.

Step 3: Initialize counter variable i to 1 and fact to 1.

Step 4: if i <=n goto step 5 otherwise goto step 7.

Step 5: Calculate fact = fact * i.

Step 6: Increment counter variable i by 1 and goto step 4.

Step 7: Write fact.

Step 8: Stop.

Program:

                             /*Factorial of a number*/

#include<iostream>

using namespace std;

int main()

{

   int num , fact = 1;

   cout<<"Enter a number: ";

    //input no. who's factorial you want

   cin>>num;

    //loop to find factorial

   for(int i=1 ; i<=num ; i++)

    

   fact = fact * i ;

    

   cout<<"Factorial of"<<num<<"is:"<<fact;

   return 0;

}  

Output:

Enter a number: 5

Factorial of 5 is: 120