无限循环 - 魔方加扰器

Question

我在python中使用Rubiks Cube scrambler时遇到了一点问题。
有我的代码：

from random import randint

moves = ["F", "F'", "R", "R'", "L", "L'", "U", "U'", "D", "D'", "B", "B'", "F2", "R2", "L2", "U2", "D2", "B2"]
scramble = []
lenght = len(scramble)
lenght_moves = len(moves) - 1
def good_move(scramble, lenght):
    if scramble[lenght]  ==  "R" or scramble[lenght] == "R'" or scramble[lenght] == "R2":
        if scramble[lenght - 1]  ==  "R" or scramble[lenght - 1] == "R'" or scramble[lenght - 1] == "R2":
            return False
    if scramble[lenght]  ==  "L" or scramble[lenght] == "L'" or scramble[lenght] == "L2":
        if scramble[lenght - 1]  ==  "L" or scramble[lenght - 1] == "L'" or scramble[lenght - 1] == "L2":
            return False
    if scramble[lenght]  ==  "F" or scramble[lenght] == "F'" or scramble[lenght] == "F2":
        if scramble[lenght - 1]  ==  "F" or scramble[lenght - 1] == "F'" or scramble[lenght - 1] == "F2":
            return False
    if scramble[lenght]  ==  "U" or scramble[lenght] == "U'" or scramble[lenght] == "U2":
        if scramble[lenght - 1]  ==  "U" or scramble[lenght - 1] == "U'" or scramble[lenght - 1] == "U2":
            return False
    if scramble[lenght]  ==  "D" or scramble[lenght] == "D'" or scramble[lenght] == "D2":
        if scramble[lenght - 1]  ==  "D" or scramble[lenght - 1] == "D'" or scramble[lenght - 1] == "D2":
            return False
    if scramble[lenght]  ==  "B" or scramble[lenght] == "B'" or scramble[lenght] == "B2":
        if scramble[lenght - 1]  ==  "B" or scramble[lenght - 1] == "B'" or scramble[lenght - 1] == "B2":
            return False
    return True


while (lenght < 20):
    print (lenght)
    print (scramble)
    random = randint(0, lenght_moves)
    if lenght - 1 >= 1:
        if good_move(scramble, lenght - 1) == False:
            print ("I'm here")
            while (good_move(scramble, lenght - 1)) != False:
                random = randint(0, lenght_moves)
                print (random)
                scramble.remove(lenght - 1)
                scramble.append(moves[random])
        else:
            scramble.append(moves[random])
    else:
        scramble.append(moves[random])
    lenght = len(scramble)
print (scramble)

所以，当我运行我的程序时，他会

  if lenght - 1 >= 1:
    if good_move(scramble, lenght - 1) == False:
        print ("I'm here")
        while (good_move(scramble, lenght - 1)) != False:
            random = randint(0, lenght_moves)
            print (random)
            scramble.remove(lenght - 1)
            scramble.append(moves[random])

他正在循环...我尝试使用"i"而不是"长度 - 1"，但它不起作用（索引超出范围等）。

moves = ["F", "F'", "R", "R'", "L", "L'", "U", "U'", "D", "D'", "B", "B'", "F2", "R2", "L2", "U2", "D2", "B2"]
scramble = []
length = len(scramble)
length_moves = len(moves) - 1
def good_move(scramble, length):
    if scramble[length]  ==  "R" or scramble[length] == "R'" or scramble[length] == "R2":
         if scramble[length - 1]  ==  "R" or scramble[length - 1] == "R'" or      scramble[length - 1] == "R2":
        return False
     if scramble[length]  ==  "L" or scramble[length] == "L'" or scramble[length] == "L2":
    if scramble[length - 1]  ==  "L" or scramble[length - 1] == "L'" or      scramble[length - 1] == "L2":
        return False
if scramble[length]  ==  "F" or scramble[length] == "F'" or scramble[length] == "F2":
    if scramble[length - 1]  ==  "F" or scramble[length - 1] == "F'" or scramble[length - 1] == "F2":
        return False
if scramble[length]  ==  "U" or scramble[length] == "U'" or scramble[length] == "U2":
    if scramble[length - 1]  ==  "U" or scramble[length - 1] == "U'" or scramble[length - 1] == "U2":
        return False
if scramble[length]  ==  "D" or scramble[length] == "D'" or scramble[length] == "D2":
    if scramble[length - 1]  ==  "D" or scramble[length - 1] == "D'" or scramble[length - 1] == "D2":
        return False
if scramble[length]  ==  "B" or scramble[length] == "B'" or scramble[length] == "B2":
    if scramble[length - 1]  ==  "B" or scramble[length - 1] == "B'" or scramble[length - 1] == "B2":
        return False
return True


i = 0
while (i < 20):
    print (length)
    print (scramble)
    random = randint(0, length_moves)
    if i >= 2:
        if good_move(scramble, i) == False:
            print ("I'm here")
            while (good_move(scramble, i)) != False:
                random = randint(0, length_moves)
                print (random)
                scramble.remove(i)
                scramble.append(moves[random])
        else:
            scramble.append(moves[random])
    else:
        scramble.append(moves[random])
    i += 1
print (scramble)

例如，在第二个代码中，我输入"i"而不是长度，当我的程序满足函数时，他告诉"索引超出范围"我不知道为什么，如果我>= 2，它不能超出范围，因为"长度"（在函数中）== 1,2,3 等等和"长度 - 1" == 0,1,2。有什么想法可以解决这个问题吗？

顺便说一句。例如，正确加扰到魔方：

R2 U2 R2 B' U2 B2 R2 F' U2 L' B2 F2 U' F2 R' B D R B R'

Answer 1

    if good_move(scramble, lenght - 1) == False:
        print ("I'm here")
        while (good_move(scramble, lenght - 1)) != False:

这是第一个问题。while循环永远不会在这里进入，因为当你到达print线时good_move肯定是假的。也许你的意思是每次都有相同的条件。

    if good_move(scramble, lenght - 1) == False:
        print ("I'm here")
        while (good_move(scramble, lenght - 1)) == False:

---

        scramble.remove(lenght - 1)

这是第二个问题。 list.remove(x)不会从列表中删除list[x]。它在列表中搜索 x 的第一个实例并将其删除，无论它位于何处。如果要删除列表的最后一个元素，可以将其切掉。

            scramble = scramble[:-1]

或删除它。

            del scramble[-1]

---

现在您的程序应该正确结束。示例结果：

["F'", 'D', 'B', 'D', 'B2', "U'", 'R2', 'L2', "D'", 'B2', 'F', "R'", 'B2', 'R', "F'", "R'", "B'", 'U2', 'F', 'L2']