求教 leetcode 374， Java 解

public int guessNumber(int n) {

        int min = 1, max = n;

        while (min <= max) {
//            int mid = (min + max) / 2; 会超时
            int mid = min+(max-min ) / 2;//不超时
            int guess = guess(mid);
            if (guess == 1) {
                min = mid + 1;

            } else if (guess == -1) {
                max = mid - 1;
            } else {
                return mid;
            }
        }

        return min;
    }

请问为什么一个超时一个不超时