const binarySearch = (arr, val, start = 0, end = arr.length - 1) => { if (start > end) return -1; const mid = Math.floor((start + end) / 2); if (arr[mid] > val) return binarySearch(arr, val, start, mid - 1); if (arr[mid] < val) return binarySearch(arr, val, mid + 1, end); return mid; }; module.exports = binarySearch;