用Python解决计数原理问题的方法

colorList = [0, 1, 2, 3]
pointList = []
amount = 0


class Point(object):
  def __init__(self):
    super(Point, self).__init__()

    self.neibors = []
    self.color = None

  def paint(self, c):
    self.color = c

  def clean(self):
    self.color = None

  def getLeftOverColors(self):
    copyOfColorList = colorList[0 : 4]

    for neibor in self.neibors:
      nc = neibor.color

      if nc in copyOfColorList:
        copyOfColorList.remove(nc)

    return copyOfColorList


def main():
  global pointList

  p0 = Point()
  p1 = Point()
  p2 = Point()
  p3 = Point()
  p4 = Point()
  p5 = Point()

  p0.neibors = [p1, p2, p4]
  p1.neibors = [p0, p2, p5]
  p2.neibors = [p0, p1, p3]
  p3.neibors = [p2, p4, p5]
  p4.neibors = [p0, p3, p5]
  p5.neibors = [p4, p3, p1]

  pointList = [p0, p1, p2, p3, p4, p5]

  paintPoint(p0)

  print(amount)

def paintPoint(p):
  global amount

  colors = p.getLeftOverColors()
  lastOne = isLastOne()

  for c in colors:
    p.paint(c)

    if lastOne:
      amount += 1
    else:
      for currentNeibor in p.neibors:
        if currentNeibor.color == None:
          paintPoint(currentNeibor)

          break

  p.clean()

def isLastOne():
  global pointList

  paintedNum = 0

  for p in pointList:
    if p.color != None:
      paintedNum += 1

  return paintedNum == 5


if __name__ == "__main__":
  main()