strong_num.cpp

//if summation of factorial of each digit returns the original number then it is a strong number
#include<iostream>
using namespace std;

int factorial(int n){
    if(n==0 || n==1) {
        return 1;
    }
    else 
        return n * factorial(n-1);
}

int strongNumber(int n){
    int strong=0;
    int original=n;
    while(n!=0){
        int temp = n % 10;
        strong += factorial(temp);
        n/=10;
    }
    if(strong==original) {
        cout<<original<<" is a Strong number"<<endl;

    }
}

int main(){
    int x,y; //x=lower limit,y=upper limit
    cout << "Enter the range: ";
    cin>>x>>y;

    //strong numbers within a range
    for(int i=x; i<=y; i++){
        strongNumber(i);
    }
    return 0;    
}