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 will tell you whether the number I picked is higher or lower than your guess. You call a pre-defined API `int guess(int num)`, which returns three possible results: - `-1`: Your guess is higher than the number I picked (i.e. `num > pick`). - `1`: Your guess is lower than the number I picked (i.e. `num < pick`). - `0`: your guess is equal to the number I picked (i.e. `num == pick`). Return _the number that I picked_.   **Example 1:** **Input:** n = 10, pick = 6 **Output:** 6 ``` **Example 2:** **Input:** n = 1, pick = 1 **Output:** 1 ``` **Example 3:** **Input:** n = 2, pick = 1 **Output:** 1 ```   **Constraints:** - `1 <= n <= 231 - 1` - `1 <= pick <= n`