solves find first and last position of element in sorted array

Author: anishLearnsToCode

Diff for: README.md

@@ -38,6 +38,7 @@
 |  29  | [Divide Two Integers](https://leetcode.com/problems/divide-two-integers)                                                                                  |                                                                [![Java](assets/java.png)](src/DivideTwoIntegers.java)                                                                |                                                                                                                                   |
 |  31  | [Next Permutation](https://leetcode.com/problems/next-permutation)                                                                                        |                                                                 [![Java](assets/java.png)](src/NextPermutation.java)                                                                 |                                                                                                                                   |
 |  33  | [Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array)                                                            |                                                           [![Java](assets/java.png)](src/SearchInRotatedSortedArray.java)                                                            |                                                                                                                                   |
+|  33  | [Find First and Last Position of Element in Sorted Array](https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array)          |                                                 [![Java](assets/java.png)](src/FindFirstAndLastPositionOfElementInSortedArray.java)                                                  |                                                                                                                                   |
 |  35  | [Search Inserted Position](https://leetcode.com/problems/search-insert-position/)                                                                         |                              [![Java](assets/java.png)](src/SearchInsertPosition.java) [![Python](assets/python.png)](python/search_insert_position.py)                              |                                                                                                                                   |
 |  38  | [Count and Say](https://leetcode.com/problems/count-and-say)                                                                                              |                                       [![Java](assets/java.png)](src/CountAndSay.java) [![Python](assets/python.png)](python/count_and_say.py)                                       |                                                                                                                                   |
 |  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)                                  |                                                                                                                                   |

Diff for: src/FindFirstAndLastPositionOfElementInSortedArray.java

@@ -0,0 +1,38 @@
+// https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array
+// T: O(logN)
+// S: O(1)
+
+public class FindFirstAndLastPositionOfElementInSortedArray {
+    public int[] searchRange(int[] nums, int target) {
+        return new int[] {
+                leftMostIndex(nums, target),
+                rightMostIndex(nums, target)
+        };
+    }
+
+    private int leftMostIndex(int[] array, int target) {
+        int left = 0, right = array.length - 1, middle;
+        while (left <= right) {
+            middle = left + (right - left) / 2;
+            if (array[middle] == target) {
+                if (middle - 1 >= 0 && array[middle - 1] == target) right = middle - 1;
+                else return middle;
+            } else if (array[middle] > target) right = middle - 1;
+            else left = middle + 1;
+        }
+        return -1;
+    }
+
+    private int rightMostIndex(int[] array, int target) {
+        int left = 0, right = array.length - 1, middle;
+        while (left <= right) {
+            middle = left + (right - left) / 2;
+            if (array[middle] == target) {
+                if (middle + 1 < array.length && array[middle + 1] == target) left = middle + 1;
+                else return middle;
+            } else if (array[middle] > target) right = middle - 1;
+            else left = middle + 1;
+        }
+        return -1;
+    }
+}