Happy Numbers

Difficulty:
Medium

Tags:
arithmetic

Instructions:
Happy numbers are positive integers that follow a particular formula: take each individual digit, square it, and then sum the squares to get a new number. Repeat with the new number and eventually, you might get to a number whose squared sum is 1. This is a happy number. An unhappy number (or sad number) is one that loops endlessly. Write a function that determines if a number is happy or not.

Hidden Code:
There is hidden code with assertions that is also being run to test out your code.

Code:
 ___

 assert_equal happy_number?(7), true
 assert_equal happy_number?(986543210), true
 assert_equal happy_number?(2), false
 assert_equal happy_number?(189), false

Your Solution

Ruby 1.9.3

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