package main

func guessNumber(n int) int {
	// 二分即可 1 ~ n 相当于 0 ~ (n - 1)
	left, right := 1, n
	mid := (left + right) / 2
	for 0 != guess(mid) && left <= right {
		if 1 == guess(mid) {
			left = mid + 1
		}else if -1 == guess(mid) {
			right = mid - 1
		}
		mid = (left + right) / 2
	}
	return mid
}

func guess(num int) int {
	return 0
}