/*  NTmach.cpp
    implementation of a Number Theory Machine
*/

#include "NTmach.h"

/* set_n() ------------------------------------
 * sets data member n (a.k.a. NTmach::n) to num
 */
void NTmach::set_n(long num){ n = num; }

/* numDigits() ---------------------------------
 * returns the number of digits in NTmach::n
 * operates on a copy of n, so as not to change n
 */
int NTmach::numDigits() {
  int count = 0;       //counter for digits
  long num = n;        //copy of data member

  //count digits in n
  while(num > 0){
    num = num / 10;    //shift num right
    ++count;           //bump count
  }

  //return result
  return count;
}

bool NTmach::isPerfect(){
  return (sumOfDivisors() == n);
}

int NTmach::sumOfDivisors(){
  int pd = 2,   //possible divisor
    sum = 1;    //sum of divisors

  //generate and test divisors
  while(pd <= n / 2){
    if(n % pd == 0)
      sum += pd;
    pd++;
  }
  return sum;
}