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;
    }
}