merge: Add test cases, optamization of code, and Add description of function (#848)

* Add test cases, optamization of code, and Add description of function

* update testcase

Recursive/BinarySearch.js

@@ -1,19 +1,36 @@
 
-// https://en.wikipedia.org/wiki/Binary_search_algorithm
-// Search the integer inside the sorted integers array using Binary Search Algorithm
+/**
+ * @function BinarySearch
+ * @description Search the integer inside the sorted integers array using Binary Search Algorithm.
+ * @param {Integer[]} arr - sorted array of integers
+ * @param {Integer} low - The input integer
+ * @param {Integer} high - The input integer
+ * @param {Integer} searchValue - The input integer
+ * @return {Integer} - return index of searchValue if found else return -1.
+ * @see [BinarySearch](https://en.wikipedia.org/wiki/Binary_search_algorithm)
+ */
 
-export const BinarySearch = (intArr, searchQuery) => {
-  if (searchQuery === null || searchQuery === undefined || intArr.length === 0) {
-    return false
+const binarySearch = (arr, low = 0, high = arr.length - 1, searchValue) => {
+  if (high >= low) {
+    const mid = low + Math.floor((high - low) / 2)
+
+    // If the element is present at the middle
+    if (arr[mid] === searchValue) {
+      return mid
+    }
+
+    // If element is smaller than mid, then
+    // it can only be present in left subarray
+    if (arr[mid] > searchValue) {
+      return binarySearch(arr, low, mid - 1, searchValue)
+    }
+
+    // Else the element can only be present in right subarray
+    return binarySearch(arr, mid + 1, high, searchValue)
   }
 
-  const middleIndex = intArr.length === 1 ? 0 : Math.ceil(intArr.length / 2)
-
-  if (intArr[middleIndex] === searchQuery) {
-    return true
-  } else if (intArr.length > 1) {
-    return intArr[middleIndex] < searchQuery ? BinarySearch(intArr.slice(1, middleIndex)) : BinarySearch(intArr.slice(middleIndex))
-  } else {
-    return false
-  }
+  // We reach here when element is not present in array
+  return -1
 }
+
+export { binarySearch }