Leetcode 54. Spiral MatrixLeetcode

Given an m x n matrix, return all elements of the matrix in spiral order.

Example 1:

Input: matrix = [[1,2,3],[4,5,6],[7,8,9]] Output: [1,2,3,6,9,8,7,4,5]

Example 2:

Input: matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]] Output: [1,2,3,4,8,12,11,10,9,5,6,7]

Constraints:

• m == matrix.length
• n == matrix[i].length
• 1 <= m, n <= 10
• -100 <= matrix[i][j] <= 100

I think DFS can be the easier way to do this. However, I want to avoid recursion. Therefore, the solution I had is below.

from enum import Enum

class Direction(Enum):
    UP = 1
    DOWN = 2
    LEFT = 3
    RIGHT = 4

class Solution:
    def spiralOrder(self, matrix: List[List[int]]) -> List[int]:
        m = len(matrix)
        n = len(matrix[0])
        
        x = y = 0
        way = Direction.RIGHT
        
        result = [matrix[0][0]]
        matrix[0][0] = None
        total = m * n

        while len(result) < total:
            if way is Direction.RIGHT:
                if x + 1 == n or matrix[y][x+1] == None:
                    way = Direction.DOWN
                else:
                    x += 1
                    result.append(matrix[y][x])
                    matrix[y][x] = None

            if way is Direction.DOWN:
                if y + 1 == m or matrix[y+1][x] == None:
                    way = Direction.LEFT
                else:
                    y += 1
                    result.append(matrix[y][x])
                    matrix[y][x] = None
            
            if way is Direction.LEFT:
                if x - 1 < 0 or matrix[y][x-1] == None:
                    way = Direction.UP
                else:
                    x -= 1
                    result.append(matrix[y][x])
                    matrix[y][x] = None
            
            if way is Direction.UP:
                if y - 1 < 0 or matrix[y-1][x] == None:
                    way = Direction.RIGHT
                else:
                    y -= 1
                    result.append(matrix[y][x])
                    matrix[y][x] = None

        return result