374. Guess Number Higher or Lower | LeetCode Using Python

I solved the “374. Guess Number Higher or Lower” problem from LeetCode using Python. By leveraging a binary search algorithm, I efficiently narrow down the range of possible numbers to identify the target in logarithmic time. This approach not only highlights the power of binary search but also provides a clear, step-by-step solution for those preparing for coding interviews or looking to improve their algorithmic skills.

Check out the video above for a detailed explanation and the Python code below:

# The guess API is already defined for you.
# @param num, your guess
# @return -1 if num is higher than the picked number
#          1 if num is lower than the picked number
#          otherwise return 0
# def guess(num: int) -> int:

class Solution:
    def guessNumber(self, n: int) -> int:
        #We can easily and efficiently solve this with a binary search algorith
        #Time Complexity O(log n)
        #Space Complexity of O(1)

        left_pointer, right_pointer = 1, n

        while left_pointer <= right_pointer:
            mid_point = (right_pointer + left_pointer) // 2

            result = guess(mid_point)

            if result == 0:
                return mid_point
            
            elif result == -1:
                right_pointer = mid_point - 1

            else: #1: Your guess is lower than the number I picked (i.e. num < pick).
                left_pointer = mid_point + 1