[矩阵]螺旋数组

class Solution:
    def spiralOrder(self, matrix: List[List[int]]) -> List[int]:
        res = []

        left = 0
        right = len(matrix[0]) - 1
        down = len(matrix) - 1
        up = 0

        while left <= right and up <= down:
            if left <= right:
                for i in range(left, right + 1, 1):
                    res.append(matrix[up][i])
                up += 1
                if down >= up:
                    for i in range(up, down + 1, 1):
                        res.append(matrix[i][right])
                    right -= 1
                    if left <= right:
                        for i in range(right, left - 1, -1):
                            res.append(matrix[down][i])
                        down -= 1
                        if down >= up:
                            for i in range(down, up - 1, -1):
                                res.append(matrix[i][left])
                            left += 1

        return res