实现

JavaScript

/**
 * @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)
 */

const binarySearch = (arr, searchValue, low = 0, high = arr.length - 1) => {
  // base case
  if (high < low || arr.length === 0) return -1

  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, searchValue, low, mid - 1)
  }

  // Else the element can only be present in right subarray
  return binarySearch(arr, searchValue, mid + 1, high)
}

export { binarySearch }

参见

• BinarySearch [二分搜索]