从贪心角度理解Kruskal算法：Python实现最小生成树的核心思想

class UnionFind:
    def __init__(self, n):
        self.parent = list(range(n))
        self.size = [1] * n

    def find(self, x):
        if self.parent[x] != x:
            self.parent[x] = self.find(self.parent[x])
        return self.parent[x]

    def union(self, x, y):
        px, py = self.find(x), self.find(y)
        if px == py:
            return False
        if self.size[px] < self.size[py]:
            px, py = py, px
        self.parent[py] = px
        self.size[px] += self.size[py]
        return True

def kruskal(edges, n):
    edges = sorted(edges, key=lambda x: x[2])
    tree = []
    uf = UnionFind(n)
    for e in edges:
        if uf.union(e[0], e[1]):
            tree.append(e)
        if len(tree) == n - 1:
            break
    return tree