题目描述：
从1～n中，随便的拿出一个数字，你来猜测。
提示
提供一个guess(int num)的api，针对猜测的数字，返回三个数值。0，-1,1
- 0;猜中返回num
- -1：比猜测的数值小
- 1：比猜测的数值大
例如：
n = 10, I pick 6.
Return 6.
原文描述：
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.
思路分析：
- 明显是二分法的应用，关于二分法，看我之前的一片博客，讲的比较详细，链接如下：
Java语言实现二分法
代码：
/* The guess API is defined in the parent class GuessGame.
@param num, your guess
@return -1 if my number is lower, 1 if my number is higher, otherwise return 0
int guess(int num); */
public class Solution extends GuessGame {
public int guessNumber(int n) {
int L = 1,R = n;
while(L <= R){
int mid = L + ((R - L) >> 1);
int res = guess(mid);
if(res == 0) return mid;
else if(res == 1) L = mid + 1;
else R = mid - 1;
}
return L;
}
}更多leetcode题目，请看我的leetcode专栏。链接如下：
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