GuessHigherLower.java

/*https://leetcode.com/problems/guess-number-higher-or-lower/*/

public class Solution extends GuessGame {
    public int guessNumber(int n) {
        int start = 1, end = n;
        while (start <= end)
        {
            int mid = start+(end-start)/2;
            int result = guess(mid);
            if (result == 0) return mid;
            else if (result == 1) start = mid+1;
            else end = mid-1;
        }
        return -1;
    }
}