Add proper tests for binary search

Search/BinarySearch.js

@@ -48,8 +48,25 @@ function binarySearchIterative (arr, x, low = 0, high = arr.length - 1) {
   // if low > high => we have searched the whole array without finding the item
   return -1
 }
+function binarySearchIterativeAlternative (arr, x) {
+  let low = -1
+  let high = arr.length
+  while (low < high - 1) {
+    const mid = Math.floor((low + high) / 2)
+    if (arr[mid] < x) {
+      low = mid
+    } else {
+      high = mid
+    }
+  }
+  return arr[high] === x ? high : -1
+}
 
-export { binarySearchIterative, binarySearchRecursive }
+export {
+  binarySearchIterative,
+  binarySearchIterativeAlternative,
+  binarySearchRecursive
+}
 
 /* ---------------------------------- Test ---------------------------------- */
 
@@ -89,3 +106,9 @@ export { binarySearchIterative, binarySearchRecursive }
 // binarySearchIterative(stringArr, 'Charlie')
 // binarySearchRecursive(stringArr, 'Zulu')
 // binarySearchIterative(stringArr, 'Sierra')
+// binarySearchIterativeAlternative(arr, 3)
+// binarySearchIterativeAlternative(arr, 7)
+// binarySearchIterativeAlternative(arr, 13)
+// binarySearchIterativeAlternative(stringArr, 'Charlie')
+// binarySearchIterativeAlternative(stringArr, 'Zulu')
+// binarySearchIterativeAlternative(stringArr, 'Sierra')