leetcode:螺旋矩阵

class :
    def spiralOrder(self, matrix: List[List[int]]) -> List[int]:
        res=[]
        if len(matrix) == 0: return res
        
        m = len(matrix)
        n = len(matrix[0])
    
        u = 0
        d = m-1
        l = 0
        r = n-1  
        while(True) :
            for i in range(l,r+1):
                res.append(matrix[u][i])
            u+=1
            if(u > d) :
                break
            
            for i in range(u,d+1):
                res.append(matrix[i][r])
            r-=1
            if(l > r) :
                break
             
            for i in range(r,l-1,-1):
                res.append(matrix[d][i])
            d-=1
            if(u > d) :
                break
            
            for i in range(d,u-1,-1):
                res.append(matrix[i][l])
            l+=1
            if(l > r) :
                break
        
        return res