spiral_matrix.py

def spiralOrder(matrix):
  """
  :type matrix: List[List[int]]
  :rtype: List[int]
  """
  if len(matrix) == 0:
      return []
  if len(matrix) == 1:
      return matrix[0]
  if len(matrix[0]) == 1:
      return [i[0] for i in matrix]
  res = []
  row_s = 0; col_s = 0
  row_e = len(matrix) - 1; col_e = len(matrix[0]) - 1
  while(row_s <= row_e and col_s <= col_e):
    # L -> R
    for i in range(col_s, col_e + 1):
      res.append(matrix[row_s][i])
    row_s += 1
    # T -> B
    for i in range(row_s, row_e + 1):
      res.append(matrix[i][col_e])
    col_e -= 1
    # R -> L
    if row_s <= row_e:
      for i in range(col_e, col_s - 1, -1):
        res.append(matrix[row_e][i])
      row_e -= 1
    # B -> T
    if col_s <= col_e:
      for i in range(row_e, row_s - 1, -1):
        res.append(matrix[i][col_s])
      col_s += 1
  return res