solves happy numbr

Author: anishLearnsToCode

README.md

@@ -60,7 +60,7 @@
 | 190 | [Reverse Bits](https://leetcode.com/problems/reverse-bits) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/ReverseBits.java) | 
 | 191 | [Number of One Bits](https://leetcode.com/problems/number-of-1-bits) | Easy | [![Python](https://img.icons8.com/color/35/000000/python.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/python/number_of_1_bits.py) |
 | 198 | [House Robber](https://leetcode.com/problems/house-robber) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/HouseRobber.java) |
-| 202 | [Happy Number](https://leetcode.com/problems/happy-number) | Easy |
+| 202 | [Happy Number](https://leetcode.com/problems/happy-number) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)]() | 
 | 203 | [Remove Linked List Elements](https://leetcode.com/problems/remove-linked-list-elements) | Easy |
 | 204 | [Count Primes](https://leetcode.com/problems/count-primes) | Easy |
 | 205 | [Isomorphic Strings](https://leetcode.com/problems/isomorphic-strings) | Easy |

src/HappyNumber.java

@@ -0,0 +1,29 @@
+import java.util.HashSet;
+import java.util.Set;
+
+public class HappyNumber {
+    public static boolean isHappy(int number) {
+        return isHappy(number, new HashSet<>());
+    }
+
+    private static boolean isHappy(long number, Set<Long> sum) {
+        long sumSquaresDigits = sumDigitSquares(number);
+        if (sumSquaresDigits == 1) {
+            return true;
+        }
+        if (sum.contains(sumSquaresDigits)) {
+            return false;
+        }
+        sum.add(sumSquaresDigits);
+        return isHappy(sumSquaresDigits, sum);
+    }
+
+    private static long sumDigitSquares(long number) {
+        long result = 0;
+        while (number > 0) {
+            result += Math.pow(number % 10, 2);
+            number /= 10;
+        }
+        return result;
+    }
+}