Strong Number In C++

Source Code
Strong Number


C++ Program To Check Strong Number or Not

Strong number is a special number whose sum of the factorial of digits
is equal to the original number.

Example:
Given Number : 145
It is a Strong Nuumber.
Since: 1! + 4! + 5! = 145
1! = 1*1 = 1
4! = 1*2*3*4 = 24
5! = 1*2*3*4*5 = 120
Example:
Given Number : 125
It is Not a Strong Nuumber.
Since:
1! + 2! + 5! = 123
1! = 1*1 = 1
2! = 1*2 = 2
5! = 1*2*3*4*5 = 120

To check if a number is a Strong Number in C++
you can use the following algorithm:
  1. Read the input number.
  2. Create a copy of the input number.
  3. Initialize a variable sum to 0.
  4. While the given number is not equal to 0,perform the following steps:
    • Get the last digit of the num by using the modulo operator (%).
    • Calculate the factorial of the last digit and add it to the sum.
    • Divide the num by 10 to remove the last digit.
  5. Check if the sum is equal to the copy number.
    • If they are equal, the number is a Strong Number.
      Otherwise, it is not.
  6. Print the result.
Here is an example implementation in C++:

Source Code

// C++ Program To Check Strong Number or Not
#include<iostream.h>
#include<conio.h>
   void main()
      {
         int num , Rd , i , fact , sum = 0 , ncopy ;
         cout<<"Enter a Number To Check : ";
         cin>>num;
         ncopy=num;
         while( num!=0 )
              {
                 Rd   = num % 10 ;
                 fact = 1;
                    for( i=1; i<=Rd; i++ )
                        {
                           fact = fact * i ;
                        }
                 sum = sum + fact ;
                 num = num / 10;
              }
        if ( sum==ncopy )
           cout<<"It is a Strong Number . ";
        else
           cout<<"It is Not a Strong Number . ";
        getch();
      }

Output

Sample Input :
Enter a Number To Check : 145
Sample Output:
It is a Strong Number

Sample Input :
Enter a Number To Check : 123
Sample Output:
It is Not a Strong Number