Introduction

In this blog post, we will explore how to solve the LeetCode problem "2833" using AI. LeetCode is a popular platform for preparing for coding interviews, and with the help of AI tools like Chatmagic, we can generate solutions quickly and efficiently - helping you pass the interviews and get the job offer without having to study for months.

Problem Statement

You are given a string moves of length n consisting only of characters 'L', 'R', and ''. The string represents your movement on a number line starting from the origin 0. In the ith move, you can choose one of the following directions: move to the left if moves[i] = 'L' or moves[i] = '' move to the right if moves[i] = 'R' or moves[i] = '_' Return the distance from the origin of the furthest point you can get to after n moves. Example 1: Input: moves = "L_RLR" Output: 3 Explanation: The furthest point we can reach from the origin 0 is point -3 through the following sequence of moves "LLRLLLR". Example 2: Input: moves = "_RLL" Output: 5 Explanation: The furthest point we can reach from the origin 0 is point -5 through the following sequence of moves "LRLLLLL". Example 3: Input: moves = "__" Output: 7 Explanation: The furthest point we can reach from the origin 0 is point 7 through the following sequence of moves "RRRRRRR". Constraints: 1 <= moves.length == n <= 50 moves consists only of characters 'L', 'R' and '_'.

Explanation

Here's the breakdown of the solution:

• Maximize the distance: The goal is to maximize the absolute distance from the origin. This means we want to go as far to the left or as far to the right as possible.
• Greedy approach: A greedy strategy will be employed. Count the number of 'R' moves, 'L' moves, and '' moves. 'R' moves contribute positively to the distance, 'L' moves contribute negatively, and '' moves can be used either to maximize the positive distance (treat as 'R') or to maximize the negative distance (treat as 'L').

• Calculate both extremes: Calculate the maximum possible distance to the right (by treating all '' as 'R') and the maximum possible distance to the left (by treating all '' as 'L'). Return the absolute value of the maximum of these two extremes.

• Runtime Complexity: O(n), where n is the length of the moves string. Storage Complexity: O(1).

Code

    def furthestPoint(moves: str) -> int:
    """
    Calculates the maximum distance from the origin after a series of moves.

    Args:
        moves: A string representing the moves, consisting of 'L', 'R', and '_'.

    Returns:
        The maximum distance from the origin.
    """

    r_count = 0
    l_count = 0
    underscore_count = 0

    for move in moves:
        if move == 'R':
            r_count += 1
        elif move == 'L':
            l_count += 1
        else:
            underscore_count += 1

    max_right = r_count + underscore_count - l_count
    max_left = r_count - l_count - underscore_count

    return max(abs(max_right), abs(max_left))