📅  最后修改于: 2022-03-11 15:04:12.128000             🧑  作者: Mango
const arr = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30];
const binarySearch = (arr, x , start=0, end=arr.length) => {
if(end < start) return -1;
let mid = Math.floor((start + end) / 2);
if(arr[mid] === x) return mid;
if(arr[mid] < x) return binarySearch(arr, x, mid+1, end);
else return binarySearch(arr, x , start, mid-1);
}
console.log(arr[binarySearch(arr,8)]);