Introduction

In this blog post, we will explore how to solve the LeetCode problem "3248" 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

There is a snake in an n x n matrix grid and can move in four possible directions. Each cell in the grid is identified by the position: grid[i][j] = (i * n) + j. The snake starts at cell 0 and follows a sequence of commands. You are given an integer n representing the size of the grid and an array of strings commands where each command[i] is either "UP", "RIGHT", "DOWN", and "LEFT". It's guaranteed that the snake will remain within the grid boundaries throughout its movement. Return the position of the final cell where the snake ends up after executing commands. Example 1: Input: n = 2, commands = ["RIGHT","DOWN"] Output: 3 Explanation: 0 1 2 3 0 1 2 3 0 1 2 3 Example 2: Input: n = 3, commands = ["DOWN","RIGHT","UP"] Output: 1 Explanation: 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7 8 Constraints: 2 <= n <= 10 1 <= commands.length <= 100 commands consists only of "UP", "RIGHT", "DOWN", and "LEFT". The input is generated such the snake will not move outside of the boundaries.

Explanation

• Core Idea: Simulate the snake's movement step-by-step according to the given commands, updating its position (row and column) in the grid.
  • Position Tracking: Maintain row and column variables to represent the snake's current position, avoiding direct index calculation for better readability and maintainability.
  • Movement Logic: Use conditional statements to update row and column based on each command.

• Runtime Complexity: O(m), where m is the number of commands. Storage Complexity: O(1).

Code

    def snake_final_position(n: int, commands: list[str]) -> int:
    """
    Calculates the final position of a snake in an n x n grid after executing a series of commands.

    Args:
        n: The size of the grid.
        commands: A list of strings, where each string is a command ("UP", "RIGHT", "DOWN", or "LEFT").

    Returns:
        The final position of the snake in the grid.
    """

    row = 0
    col = 0

    for command in commands:
        if command == "UP":
            row -= 1
        elif command == "DOWN":
            row += 1
        elif command == "RIGHT":
            col += 1
        elif command == "LEFT":
            col -= 1

    return (row * n) + col