Package g0201_0300.s0202_happy_number

Class Solution

java.lang.Object

g0201_0300.s0202_happy_number.Solution

public class Solution
extends Object

202 - Happy Number.<p>Easy</p> <p>Write an algorithm to determine if a number <code>n</code> is happy.</p> <p>A <strong>happy number</strong> is a number defined by the following process:</p> <ul> <li>Starting with any positive integer, replace the number by the sum of the squares of its digits.</li> <li>Repeat the process until the number equals 1 (where it will stay), or it <strong>loops endlessly in a cycle</strong> which does not include 1.</li> <li>Those numbers for which this process <strong>ends in 1</strong> are happy.</li> </ul> <p>Return <code>true</code> <em>if</em> <code>n</code> <em>is a happy number, and</em> <code>false</code> <em>if not</em>.</p> <p><strong>Example 1:</strong></p> <p><strong>Input:</strong> n = 19</p> <p><strong>Output:</strong> true</p> <p><strong>Explanation:</strong></p> <p>1² + 9² = 82</p> <p>8² + 2² = 68</p> <p>6² + 8² = 100</p> <p>1² + 0² + 0² = 1</p> <p><strong>Example 2:</strong></p> <p><strong>Input:</strong> n = 2</p> <p><strong>Output:</strong> false</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= n <= 2³¹ - 1</code></li> </ul>

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
boolean	isHappy(int n)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Solution

public Solution()

Method Details

isHappy

public boolean isHappy(int n)