added function

Author: mauricechouam

Find First and Last Position of Element in Sorted Array/code.js

@@ -21,6 +21,11 @@ var searchRange = function(nums, target) {
     // reset low and high
     low = 0, high = nums.length-1;
 
-   
+    // find the end
+    while(low <= high) {
+        mid = Math.floor((low+high)/2);
+        if(nums[mid] <= target) low = mid+1;
+        else high = mid-1;
+    }
     return [start, high];
 };