text: """
  
  Write an algorithm to determine if a number is "happy".
  
  A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Those numbers for which this process ends in 1 are happy numbers.
  
  Example: 19 is a happy number
  
  12 + 92 = 82
  82 + 22 = 68
  62 + 82 = 100
  12 + 02 + 02 = 1
  
  """
  
  class Solution:
  	
  	# @param {integer} n
  	# @return {boolean}
  	def isHappy(self, n):
  		
  		# hold the numbers that have been calculated so far
  		visited = set()
  		
  		while n != 1:
  			
  			# calc next happy iteration
  			happy = 0
  			while n > 0:
  				digit = n % 10
  				happy += (digit * digit)
  				n /= 10
  			
  			# check for cycles
  			if happy in visited:
  				return False
  			
  			# move to next iteration
  			visited.add(happy)
  			n = happy	
  			
  		return True
  	
  	
  
  s = Solution()
  print s.isHappy(19)