54_spiral_matrix.py

class Solution:
    def spiralOrder(self, matrix: List[List[int]]) -> List[int]:
        visited = [[False for i in range(len(matrix[0]))] for j in range(len(matrix))]
        direction_arr = [[0, 1], [1, 0], [0, -1], [-1, 0]]
        direction = i = j = 0
        total_num = len(matrix) * len(matrix[0])
        ans = []
        while len(ans) != total_num:
            ans.append(matrix[i][j])
            visited[i][j] = True
            next_i = i + direction_arr[direction][0]
            next_j = j + direction_arr[direction][1]
            if (0 <= next_i < len(matrix)) and (0 <= next_j < len(matrix[0])) and (visited[next_i][next_j] == False):
                i = next_i
                j = next_j
            else:
                direction = (direction + 1) % 4
                i += direction_arr[direction][0]
                j += direction_arr[direction][1]
        return ans

'''
    This is my personal record of solving Leetcode Problems. 
    If you have any questions, please discuss them in [Issues](https://github.com/mengxinayan/leetcode/issues).
    Copyright (C) 2020-2022  mengxinayan

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
'''