Add solution #34

Author: JoshCrozier

README.md

@@ -30,6 +30,7 @@
 28|[Implement strStr()](./0028-implement-strstr.js)|Easy|
 31|[Next Permutation](./0031-next-permutation.js)|Medium|
 33|[Search in Rotated Sorted Array](./0033-search-in-rotated-sorted-array.js)|Medium|
+34|[Find First and Last Position of Element in Sorted Array](./0034-find-first-and-last-position-of-element-in-sorted-array.js)|Medium|
 35|[Search Insert Position](./0035-search-insert-position.js)|Easy|
 36|[Valid Sudoku](./0036-valid-sudoku.js)|Medium|
 41|[First Missing Positive](./0041-first-missing-positive.js)|Hard|

solutions/0034-find-first-and-last-position-of-element-in-sorted-array.js

@@ -0,0 +1,40 @@
+/**
+ * 34. Find First and Last Position of Element in Sorted Array
+ * https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array/
+ * Difficulty: Medium
+ *
+ * Given an array of integers nums sorted in non-decreasing order, find the starting and
+ * ending position of a given target value.
+ *
+ * If target is not found in the array, return [-1, -1].
+ *
+ * You must write an algorithm with O(log n) runtime complexity.
+ */
+
+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number[]}
+ */
+var searchRange = function(nums, target) {
+  let start = 0;
+  let end = nums.length - 1;
+
+  while (start <= end) {
+    const middle = Math.floor((start + end) / 2);
+    if (target > nums[middle]) {
+      start = middle + 1;
+    } else {
+      end = middle - 1;
+    }
+  }
+
+  if (nums[start] !== target) {
+    return [-1, -1];
+  }
+
+  while (nums[start - 1] === target) start--;
+  while (nums[end + 1] === target) end++;
+
+  return [start, end];
+};