Validate Binary Tree

https://leetcode.com/problems/validate-binary-tree-nodes/

Union Find Approach

#check two conditions: 
# (1) UnionFind Disjoint Set Count 1
# (2) In-degree sum of all nodes equal to n-1
class UnionFind(object):
    def __init__(self,n):
        self.parents = list(range(n))
        self.count = n
    
    def find(self,x):
        if x != self.parents[x]:
            self.parents[x] = self.find(self.parents[x])
        return self.parents[x]
    
    def union(self,x,y):
        xSet = self.find(x)
        ySet = self.find(y)
        self.parents[ySet] = xSet
        if xSet == ySet:
            return False
        self.count-=1
        return True
    
class Solution:
    def validateBinaryTreeNodes(self, n: int, leftChild: List[int], rightChild: List[int]) -> bool:
        inDegree = n * [0]
        uf = UnionFind(n)
        
        for parent, nodes in enumerate(zip(leftChild,rightChild)):
            l,r = nodes
            if l != -1:
                uf.union(parent,l)
                inDegree[l]+=1
            
            if r != -1:
                uf.union(parent,r)
                inDegree[r] +=1
        
        return sum(inDegree) == n-1 and uf.count==1