Merge pull request #2620 from aadil42/patch-63

Author: aakhtar3

Diff for: javascript/0034-find-first-and-last-position-of-element-in-sorted-array.js

@@ -0,0 +1,47 @@
+/**
+ * Binary Search
+ * https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array/
+ * Time O(log(n)) | Space O(1)
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number[]}
+ */
+var searchRange = function(nums, target) {
+    
+    const result = [];
+
+    result.push(binarySearch(true, nums, target));
+    result.push(binarySearch(false, nums, target));
+
+    return result;
+};
+
+var binarySearch = (isLeftBias, nums, target) => {
+      let left = 0;
+      let right = nums.length - 1;
+      let index = -1;
+
+      while(left <= right) {
+        
+        const mid = (left + right) >> 1;
+
+        if(target > nums[mid]) {
+          left = mid+1;
+        }
+        if(target < nums[mid]) {
+          right = mid-1;
+        }
+        
+        const isTarget = target === nums[mid];
+        if(isTarget) {
+          if(isLeftBias) {
+            index = mid;
+            right = mid - 1;
+          } else {
+            index = mid;
+            left = mid + 1;
+          }
+        }
+      }
+      return index;
+}