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 :

Input: n = 10, pick = 6
Output: 6

Solution

public class Solution extends GuessGame {
    public int guessNumber(int n) {
        int lo = 1;
        int hi = n;
        int mid = 0;
        int result = 2;
        while(hi - lo > 1){
            mid = lo + (hi-lo)/2;
            result = guess(mid);
            if(result == 0){
                return mid;
            }else if (result == 1){//higher
                lo = mid+1;
            }else if (result == -1){
                hi = mid-1;
            }
        }
    
        if( guess(lo) == 0){
            return lo;
        }else
            return hi;    
        
    }
}