#include <iostream>
using namespace std;
/*
 * This C++ program determines if a number is happy or unhappy.
 *
 * @creator g.d.thurman
 * @created 2008.03.08
 */
int main(int argc, char* argv[]) {
   int n;
   bool ishappy(int);

   for (int i = 1; i < argc; i++) {
      if ((n = atoi(argv[i])) > 0)
         cout << n << " is " << (ishappy(n) ? "happy" : "unhappy") << endl; 
   }
   return 0;
}
/*
 * NumberGossip.com defines "happy number" as follows:  "One can take 
 * the sum of the squares of the digits of a number.  Those numbers are 
 * happy for which iterating this operation eventually leads to 1."
 */
bool ishappy(int n) {
   int sum_digits_squared(int);
   while ((n = sum_digits_squared(n)) > 0) {
      if (n == 1) return true;
      if (n == 4) return false;   // concerned about infinite loop
   }
   return false;
}
/*
 * Sum the square of the digits of 'n'.  Example:  if n == 216,
 * return 41 (2-squared + 1-squared + 6-squared [4 + 1 + 36]). 
 */
int sum_digits_squared(int n) {
   int sum = 0, a, orig = n;
   while (n > 0) {
      a = n % 10;
      sum = sum + a * a;
      n = n / 10;
   }
   return sum;
}