LeetCode 1971 Find if Path Exists - Implementation

Union-Find with path compression.

class UnionFind: def init(self, n): self.parent = list(range(n)) self.rank = [0] * 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
    if self.rank[px] < self.rank[py]:
        px, py = py, px
    self.parent[py] = px
    if self.rank[px] == self.rank[py]:
        self.rank[px] += 1

def validPath(n, edges, source, destination): uf = UnionFind(n) for u, v in edges: uf.union(u, v) return uf.find(source) == uf.find(destination)

$O(E \cdot \alpha(n))$ time, $O(n)$ space.