[leetcode] problem 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

Code

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public int (int n) {
    int left = 1;
    int right = n;

    while (left < right) {
        int mid = left + (right - left) / 2;
        int result = guess(mid);

        if (result == 0)
            return mid;
        else if (result == -1)
            right = mid - 1;
        else
            left = mid + 1;
    }
    
    return left;
}