374. Guess Number Higher or Lower

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.

/* 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 top=n,bot=0,guess = (top+bot)/2,status=guess(guess);
while(status!=0){
if(status<0){
top=guess-1;
guess=(int)(((long)top+(long)bot)/2);
}
else {
bot=guess+1;
guess=(int)(((long)top+(long)bot)/2);
}
status=guess(guess);
}return guess;
}
}