(union_find) 323. Number of connected components in an Undirected Graph

(premium)
https://leetcode.com/problems/number-of-connected-components-in-an-undirected-graph/

class Solution:
	def countComponents(self, n:int, edges: List[List[int]]) -> int:
    	parent = [i for i in range(n)]
        rank = [1] * n
        
        def find(n1):
        	res = n1
            
            while res != par[res]:
            	parent[res] = parent[parent[res]]
                res = parent[res]
            return res
        
        def union(n1, n2):
        	p1, p2 = find(n1), find(n2)
            
            if p1 == p2:
            	return 0
            
            if rank[p2] > rank[p1]:
            	parent[p1] = p2
                rank[p2] += rank[p1]
            else:
            	parent[p2] = p1
                rank[p1] += ranke[p2]
            return 1
        
        res = n
        for n1, n2 in edges:
            res = union(n1, n2)
        return res

(union_find) 547. Number of Provinces

https://leetcode.com/problems/number-of-provinces/

class Solution:
    def findCircleNum(self, isConnected: List[List[int]]) -> int:
		pass