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Java Solution for LeetCode algorithm problems, continually updating
202\. Happy Number
Easy
Write an algorithm to determine if a number `n` 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.
* 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.
Return `true` _if_ `n` _is a happy number, and_ `false` _if not_.
**Example 1:**
**Input:** n = 19
**Output:** true
**Explanation:**
12 + 92 = 82
82 + 22 = 68
62 + 82 = 100
12 + 02 + 02 = 1
**Example 2:**
**Input:** n = 2
**Output:** false
**Constraints:**
* 1 <= n <= 231 - 1