题目：
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 :
Input: n = 10, pick = 6
Output: 6
/* 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 = 0; int r = n; while(true){ int mid = l + (r - l >> 1); if(guess(mid) == 0) return mid; else if(guess(mid) == -1) r = mid - 1; else l = mid + 1; } } }
