# 【Easy】662. Guess Number Game

> We are playing the Guess Game. The game is as follows: I pick a number from 1 to n. You have to guess which number I picked. Every time you guess wrong, I'll tell you whether the number is higher or lower. You call a pre-defined API guess(int num) which returns 3 possible results (-1, 1, or 0):

**Example:**

n = 10, I pick 4 (but you don't know)

Return 4. Correct !

## 解题思路

常规二分法。

## 时间空间复杂度

O(nlogn) + S(1)
