打卡群刷题总结0710—— 螺旋矩阵

class Solution(object):
    def spiralOrder(self, matrix):
        """
        :type matrix: List[List[int]]
        :rtype: List[int]
        """
        if len(matrix) == 0:
            return []
        if len(matrix) == 1:
            return matrix[0]

        top, bottom = 0, len(matrix) - 1
        left, right = 0, len(matrix[0]) - 1
        res = []
        while top <= bottom and left <= right:
            if top <= bottom:
                # top：left->right
                for j in range(left, right + 1):
                    res.append(matrix[top][j])
                top += 1
            if left <= right:
                # right: top -> bottom
                for i in range(top, bottom + 1):
                    res.append(matrix[i][right])
                right -= 1
            if top <= bottom:
                # bottom: right -> left
                for j in range(right, left - 1, -1):
                    res.append(matrix[bottom][j])
                bottom -= 1
            if left <= right:
                # left: bottom -> top
                for i in range(bottom, top - 1, -1):
                    res.append(matrix[i][left])
                left += 1
        return res