Question

Consider the following definition:
A positive integer num is called a factorion if it equals to the sum of the factorials of its digits.
For example, 145 is a factorion because 1! + 4! + 5! = 1 + 24 + 120 = 145.
Write a program that asks the user to enter a positive integer and reports if that number is a
factorion or not.
Reminder: the factorial of a positive integer n, denoted by n!, is the product of all positive
integers less than or equal to n: ?! = ? × (? − 1) × (? − 2) × … × 2 × 1.
For example, 5! = 5 × 4 × 3 × 2 × 1 = 120
Also, the value of 0! is defined as 1
Your program should interact with the user exactly as demonstrated in the following two
executions:
Execution example 1:
Please enter a positive integer:
145
145 is a factorion

Answer 1

Code:

#include<iostream>
using namespace std;
int main()
{
   int n,j;
   cout << "Please enter a positive Integer : ";
   cin >> n; //taking input number from user
   int dummy=n,sum=0; //storing it in dummy variable,initialize sum to zero
   while (n!=0) //iterate loop till the number is equal to zero
       {
       int dig=n%10; //extract each digit from number
       if (dig!=0) //if number!=0 then calculate factorial of that number
           {
           int fact=1;
           for (j=1;j<=dig;j++) //calculate factorial
               fact=fact*j;
           sum=sum+fact; //finally add that factorial value to sum
           }
       else
           sum=sum+1; //if digit is zero then directly add 1 to sum since 0!=1
       n=n/10; //divide n with 10 get the next digits number
       }
   if (dummy==sum) //finally check if the sum and dummy are equal then print below
       cout << sum << " is a factorion" << endl;
   return 0;
}

Code and Output Screenshots:

Note : if you have any queries please post a comment thanks a lot...