递归
function binarySearch(arr: number[], target: number, left: number = 0, right: number = arr.length - 1): number {
if (left > right) {
return -1
}
const mid = Math.floor((left + right) / 2)
if (arr[mid] === target) {
return mid
}
if (arr[mid] < target) {
return binarySearch(arr, target, mid + 1, right)
}
return binarySearch(arr, target, left, mid - 1)
}
const arr = [-1, 0, 1, 2, 3, 4, 5, 6, 11, 44, 56, 77]
console.log(binarySearch(arr, 44)) // 9
console.log(binarySearch(arr, 99)) // -1
