solves pow(x, n )

Author: anishLearnsToCode

README.md

@@ -50,6 +50,7 @@
 |  47  | [Permutations II](https://leetcode.com/problems/permutations-ii)                                                                                          |                                                                 [![Java](assets/java.png)](src/PermutationsII.java)                                                                  |                                                                                                                                   |
 |  48  | [Rotate Image](https://leetcode.com/problems/rotate-image)                                                                                                |                                                                   [![Java](assets/java.png)](src/RotateImage.java)                                                                   |                                                                                                                                   |
 |  49  | [Group Anagrams](https://leetcode.com/problems/group-anagrams)                                                                                            |                                                                  [![Java](assets/java.png)](src/GroupAnagrams.java)                                                                  |                                                                                                                                   |
+|  50  | [Pow(x,n)](https://leetcode.com/problems/powx-n)                                                                                                          |                                                                      [![Java](assets/java.png)](src/Powxn.java)                                                                      |                                                                                                                                   |
 |  53  | [Maximum SubArray](https://leetcode.com/problems/maximum-subarray)                                                                                        |                                 [![Java](assets/java.png)](src/MaximumSubArray.java) [![Python](assets/python.png)](python/maximum_sum_subarray.py)                                  |                                                                                                                                   |
 |  55  | [Jump Game](https://leetcode.com/problems/jump-game)                                                                                                      |                                                                    [![Java](assets/java.png)](src/JumpGame.java)                                                                     |                                                                                                                                   |
 |  58  | [Length of Last Word](https://leetcode.com/problems/length-of-last-word)                                                                                  |                                 [![Java](assets/java.png)](src/LengthOfLastWord.java) [![Python](assets/python.png)](python/length_of_last_word.py)                                  |                                                                                                                                   |

src/Powxn.java

@@ -0,0 +1,17 @@
+// https://leetcode.com/problems/powx-n
+// T: O(log(n))
+// S: O(1)
+
+public class Powxn {
+    public double myPow(double x, int n) {
+        if (n >= 0) return power(x, n);
+        return 1 / power(x, -n);
+    }
+
+    private double power(double x, int n) {
+        if (n == 0) return 1;
+        if (n == 1) return x;
+        double half = power(x, n / 2);
+        return half * half * (n % 2 == 0 ? 1 : x);
+    }
+}