Added Happy Number

Author: anonimak

LeetcodeProblems/Algorithms/Happy_Number.js

@@ -0,0 +1,49 @@
+/**
+Happy Number
+https://leetcode.com/problems/happy-number/
+
+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
+
+
+ */
+
+/**
+ * @param {number} n
+ * @return {boolean}
+ */
+var isHappy = function(n) {
+    return checkHappyNumber(n);
+};
+
+function checkHappyNumber(n){
+    strNumber = n.toString();
+    splitNumber = strNumber.split("");
+    if(splitNumber.length <= 1){
+      return (n <= 1)? true:false;
+    }
+    const digit = splitNumber.reduce((a,b)=> parseInt(a) + Math.pow(parseInt(b),2),0);
+    return checkHappyNumber(digit)
+}
+
+module.exports.isHappy = isHappy;

LeetcodeProblemsTests/Algorithms/Happy_Number_Test.js

@@ -0,0 +1,9 @@
+const assert = require('assert');
+const isHappy = require('../../LeetcodeProblems/Algorithms/Happy_Number').isHappy;
+
+var test = function () {
+  assert.equal(isHappy(19),true);
+  assert.equal(isHappy(2),false);
+}
+
+module.exports.test = test;

README.md

@@ -86,6 +86,7 @@ To run a specific problem in your console run  `node <problem_file_path>` (e.g.
 | [Permutations With Duplicates ](/LeetcodeProblems/Algorithms/Permutations_With_Duplicates.js)                   |        | |
 | [Deletion Distance](/LeetcodeProblems/Algorithms/Deletion_Distance.js)                                          |        | |
 | [Award Budget Cuts](/LeetcodeProblems/Algorithms/Award_Budget_Cuts.js)                                          |        | |
+| [Happy Number](https://leetcode.com/problems/happy-number/)                                                     | Easy   | https://leetcode.com/problems/happy-number/ |
 
 ### Sorting Algorithms
 | Algoritmhs |