374. Guess Number Higher or Lower [easy] (Python)

题目链接

https://leetcode.com/problems/guess-number-higher-or-lower/

题目原文

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):
-1 : My number is lower
1 : My number is higher
0 : Congrats! You got it!

Example:
n = 10, I pick 6.
Return 6.

题目翻译

猜数字游戏。游戏规则是这样的：我从1到n中挑选一个数，你来猜我挑的数是多少。每次你猜错了我都会告诉你正确数字是更大还是更小。
你写的函数可以调用一个预先实现的guess(int num)的接口，它能返回-1，0，1三个可能值：-1表示正确数字更小；1表示正确数字更大；0表示猜对了。
比如：当n=10，我选的数是6时，你的函数也应该返回6。

思路方法

本题的关键是理解题意。。。

思路一<