class Solution:
    def spiralOrder(self, matrix: List[List[int]]) -> List[int]:
        result = []
        while matrix:
            result.extend(list(matrix.pop(0)))
            matrix = list(zip(*matrix))
            matrix.reverse()
        return result

class Solution:
    class Solution:
    def spiralOrder(self, matrix:[[int]]) -> [int]:
        if not matrix: 
            return []
        l, r, t, b, res = 0, len(matrix[0])-1, 0, len(matrix)-1, []
        while True:
            for i in range(l, r+1): 
                res.append(matrix[t][i]) # left to right
            t += 1
            if t > b: 
                break
            for i in range(t, b + 1): 
                res.append(matrix[i][r]) # top to bottom
            r -= 1
            if l > r: 
                break
            for i in range(r, l - 1, -1): 
                res.append(matrix[b][i]) # right to left
            b -= 1
            if t > b: 
                break
            for i in range(b, t - 1, -1): 
                res.append(matrix[i][l]) # bottom to top
            l += 1
            if l > r: 
                break
        return res