给定一组格点，有多少组点？

Question

这个想法是给定平面上的一组格点，确定给定集合中有多少“组”点。 一组点定义如下：

Given a set S of lattice points, 
it is said that these points form a group of points if and only if:
for each a of S the distance of the nearest point(s) is 1

该函数必须返回一个包含所有现有点组的列表。

input: --> point: list
output: --> group: list

如果有可能获得更好的算法，因为我不确定这段代码是否适用于每组点。

我的代码是这样的

def walk_point_path(points):
    groups = []
    points_x = sorted(points, key=lambda x: x[1])
    visited = [points_x[0]]
    q = [points_x[0]]
    while points_x:
        while q:
            x, y = q.pop()
            for x, y in (x, y - 1), (x, y + 1), (x - 1, y), (x + 1, y):
                if [x, y] not in visited and [x, y] in points_x:
                    q.append([x, y])
                    visited.append([x, y])
        groups.append(visited)
        for point in visited:
            points_x.remove(point)
        if len(points_x) > 0:
            q = [points_x[0]]
            visited = [points_x[0]]
    return groups

Answer 1

考虑connected-components labeling 算法的一些好的实现。

您当前的方法利用 Flood-fill 算法 (One component at a time kind) 来分组获得积分。