fix: added parameters to iterative binary search

Author: Fechuli

search/binary_search.ts

@@ -16,18 +16,18 @@
 
 export const binarySearchIterative = (
   array: number[],
-  target: number
+  target: number,
+  start: number = 0,
+  end: number = array.length - 1
 ): number => {
   if (array.length === 0) return -1
 
-  // declare pointers for the start, middle and end indices
-  let start = 0,
-    end = array.length - 1,
-    middle = (start + end) >> 1
-
   // ensure the target is within the bounds of the array
   if (target < array[start] || target > array[end]) return -1
 
+  // declare pointers for the middle index
+  let middle = (start + end) >> 1
+
   while (array[middle] !== target && start <= end) {
     // if the target is less than the middle value, move the end pointer to be middle -1 to narrow the search space
     // otherwise, move the start pointer to be middle + 1

search/exponential_search.ts

@@ -1,9 +1,16 @@
+import { binarySearchIterative } from './binary_search'
+
 /**
  * @description Exponential search algorithm for a sorted array.
  *
  * The algorithm searches for a specific value in a sorted array by first finding a range
  * where the value may be present and then performing a binary search within that range.
  *
+ * Compared with binary search, exponential search can be more convenient and advantageous
+ * in cases where the element to be searched is closer to the beginning of the array, 
+ * thus avoiding several comparisons that would make the search more verbose. 
+ * Exponential search doubles the search time with each iteration.
+ *
  * @param {number[]} array - sorted list of numbers
  * @param {number} x - target number to search for
  * @return {number | null} - index of the target number in the list, or null if not found
@@ -26,24 +33,9 @@ export const exponentialSearch = (
     i = i * 2
   }
 
-  return binarySearch(array, x, i / 2, Math.min(i, arrayLength - 1))
-}
+  const start = Math.floor(i / 2)
+  const end = Math.min(i, arrayLength - 1)
+  const result = binarySearchIterative(array, x, start, end)
 
-const binarySearch = (
-  array: number[],
-  x: number,
-  start: number,
-  end: number
-): number | null => {
-  while (start <= end) {
-    const mid = Math.floor((start + end) / 2)
-    if (array[mid] === x) {
-      return mid
-    } else if (array[mid] < x) {
-      start = mid + 1
-    } else {
-      end = mid - 1
-    }
-  }
-  return null
+  return result !== -1 ? result : null
 }