算法起步-递归-汉诺塔

汉诺塔应用到了最简单的迭代,最基本的代码如下：

def hannoi(n, a, c, b, step):
    if n != 0:
        hannoi(n - 1, a, b, c, step)
        print("Moving form %s to %s" % (a, b))
        hannoi(n - 1, c, a, b, step)


hannoi(5, "A", "B", "C")

然后看到有大佬放出了动画演示的demo：https://www.cnblogs.com/ReganWhite/p/10595719.html

进一步我稍作修改，给盘子添加了五个颜色，并统计运行的步数：

# coding: utf-8


import turtle


class Stack:
    def __init__(self):
        self.items = []

    def isEmpty(self):
        return len(self.items) == 0

    def push(self, item):
        self.items.append(item)

    def pop(self):
        return self.items.pop()

    def peek(self):
        if not self.isEmpty():
            return self.items[len(self.items) - 1]

    def size(self):
        return len(self.items)


def drawpole_3():  # 画出汉诺塔的poles
    t = turtle.Turtle()
    t.hideturtle()

    def drawpole_1(k):
        t.up()
        t.pensize(10)
        t.speed(100)
        t.goto(400 * (k - 1), 100)
        t.down()
        t.goto(400 * (k - 1), -100)
        t.goto(400 * (k - 1) - 20, -100)
        t.goto(400 * (k - 1) + 20, -100)

    drawpole_1(0)  # 画出汉诺塔的poles[0]
    drawpole_1(1)  # 画出汉诺塔的poles[1]
    drawpole_1(2)  # 画出汉诺塔的poles[2]


def creat_plates(n):  # 制造n个盘子
    color_list = ("black", "red", "green", "blue", "yellow")
    plates = [turtle.Turtle() for i in range(n)]
    for i in range(n):
        plates[i].up()
        plates[i].hideturtle()
        plates[i].shape("square")
        plates[i].shapesize(1, 8 - i)
        plates[i].color(color_list[(i % 5)])
        plates[i].goto(-400, -90 + 20 * i)
        plates[i].showturtle()
    return plates


def pole_stack():  # 制造poles的栈
    poles = [Stack() for i in range(3)]
    return poles


def moveDisk(plates, poles, fp, tp):  # 把poles[fp]顶端的盘子plates[mov]从poles[fp]移到poles[tp]
    mov = poles[fp].peek()
    plates[mov].goto((fp - 1) * 400, 150)
    plates[mov].goto((tp - 1) * 400, 150)
    l = poles[tp].size()  # 确定移动到底部的高度（恰好放在原来最上面的盘子上面）
    plates[mov].goto((tp - 1) * 400, -90 + 20 * l)


def moveTower(plates, poles, height, fromPole, toPole, withPole):  # 递归放盘子
    global step
    if height >= 1:
        moveTower(plates, poles, height - 1, fromPole, withPole, toPole)
        moveDisk(plates, poles, fromPole, toPole)
        step = step + 1
        poles[toPole].push(poles[fromPole].pop())
        moveTower(plates, poles, height - 1, withPole, toPole, fromPole)

    return step


my_screen = turtle.Screen()
drawpole_3()
n = int(input("请输入汉诺塔的层数并回车:\n"))
plates = creat_plates(n)
poles = pole_stack()
step = 0  # 记录移动总步数
for i in range(n):
    poles[0].push(i)
steps = moveTower(plates, poles, n, 0, 2, 1)
my_screen.exitonclick()
print("该过程共移动 %s 步" % steps)

由于采用了上面大佬的代码，最多限制8个盘子。

标签：goto,递归,self,400,算法,poles,plates,汉诺塔,def
来源： https://www.cnblogs.com/Bethuel/p/13369946.html