字典值未更新

Question

我正在实现波函数崩溃算法，我定义波如下：

wave = {divmod(n, HEIGHT): types.copy() for n in range(HEIGHT * WIDTH)}

然后，当我更新仓位的可能状态时，它不会改变。我用这个来更新它：

wave[(nx, ny)] = new  # update possibilities
wave[pos] = {chosen_type}  # collapse to one state

我想知道问题是否是使用 divmod 或 tuple 作为键，或者是否是关于在 dict 中存储集合。

这是完整的代码：

import random

WIDTH, HEIGHT = 20, 20


class TileType:
    def __init__(self, name):
        self.allowed = set()
        self.name = name

    def __repr__(self):
        return self.name

    def add_allowed(self, *types):
        for type_ in types:
            self.allowed.add(type_)
            type_.allowed.add(self)


def generate(types):
    def propagate(xy, *allowed):
        x, y = xy
        for dx, dy in [(1, 0), (-1, 0), (0, 1), (0, -1)]:
            nx, ny = x + dx, y + dy
            if 0 <= nx < WIDTH and 0 <= ny < HEIGHT:
                new = wave[(nx, ny)].union(*allowed)
                if new.difference(wave[(nx, ny)]):
                    wave[(nx, ny)] = new
                    propagate((nx, ny), *(tile.allowed for tile in new))

    # Initialize wave state
    assert len(types) > 0
    wave = {divmod(n, HEIGHT): types.copy() for n in range(HEIGHT * WIDTH)}

    while True:
        pos, entropy = min(wave.items(), key=lambda i: (len(i[1]) if len(i[1]) != 1 else 9e+9))
        entropy = len(entropy)
        assert entropy != 0
        if entropy == 9e+9:
            break
        chosen_type = tuple(wave[pos])[random.randint(0, entropy - 1)]
        print(pos, entropy, chosen_type)
        wave[pos] = {chosen_type}
        propagate(pos, chosen_type.allowed)


def main():
    t0 = TileType("0")
    t1 = TileType("1")
    t2 = TileType("2")
    t3 = TileType("3")
    t4 = TileType("4")
    
    t0.add_allowed(t4, t2)
    t1.add_allowed(t3, t4)
    t2.add_allowed(t3)
    
    generate({t0, t1, t2, t3, t4})


if __name__ == '__main__':
    main()

Answer 1

我认为字典值正在更新

主要内容有一点变化：

def generate(types):
    def propagate(xy, *allowed):
        x, y = xy
        for dx, dy in [(1, 0), (-1, 0), (0, 1), (0, -1)]:
            nx, ny = x + dx, y + dy
            if 0 <= nx < WIDTH and 0 <= ny < HEIGHT:
                new = wave[(nx, ny)].union(*allowed)
                if new.difference(wave[(nx, ny)]):
                    wave[(nx, ny)] = new
                    propagate((nx, ny), *(tile.allowed for tile in new))

    # Initialize wave state
    assert len(types) > 0
    wave = {divmod(n, HEIGHT): types.copy() for n in range(HEIGHT * WIDTH)}
    print(wave)

    while True:
        pos, entropy = min(wave.items(), key=lambda i: (len(i[1]) if len(i[1]) != 1 else 9e+9))
        print("pos", pos)
        entropy = len(entropy)
        assert entropy != 0
        if entropy == 9e+9:
            break
        chosen_type = tuple(wave[pos])[random.randint(0, entropy - 1)]
        print(pos, entropy, chosen_type)
        wave[pos] = {chosen_type}
        propagate(pos, chosen_type.allowed)
        break
    print(wave)

我得到了输出...

(0, 0): {1, 3, 2, 0, 4}, ...
pos (0, 0)
(0, 0) 5 4
{(0, 0): {4}, ...

所以字典波更新了

我不太确定你正在实现的算法，也许 while 停止条件有点不可能达到。

if entropy == 9e+9:
            break

因为 min 返回较小的值，而不是 key 返回的值。我认为熵 entropy == 9e+9 是不太可能的，这使得程序永远不会结束......