323-Number-of-Connected-Components-in-an-Undirected-Graph.py

class UnionFind:
    def __init__(self):
        self.f = {}
    
    def findParent(self,x):
        y = self.f.get(x,x)
        if x!=y:
            y = self.f[x] = self.findParent(y) 
        return y
    
    def union(self,x,y):
        self.f[self.findParent(x)] = self.findParent(y)

class Solution:
    def countComponents(self, n: int, edges: List[List[int]]) -> int:
        dsu = UnionFind()
        for a,b in edges:
            dsu.union(a,b)
        return len(set(dsu.findParent(x) for x in range(n)))