Lowest common ancestor in a tree

lowest_common_ancestor.py

class Node:
    def __init__(self, val, parent = None):
        self.val = val
        self.parent = parent
        self.left = None
        self.right = None
        
        
class Tree:
    def __init__(self, val_list):
        self.root = Node(val_list.pop(0))
        q = [self.root]
        while val_list:
            temp = q.pop(0)
            temp.left = Node(val_list.pop(0), temp)
            q.append(temp.left)
            if val_list:
                temp.right = Node(val_list.pop(0), temp)
                q.append(temp.right)
        
    
    def findNode(self, a):
        if self.root.val == a:
            return self.root

        queue = [self.root]
        while queue:
            temp = queue.pop(0)
            if temp.val == a:
                return temp
            if temp.left != None:
                queue.append(temp.left)
            if temp.right != None:
                queue.append(temp.right)
        return None


    def findLCA(self, a, b):
        a = self.findNode(a)
        b = self.findNode(b)
        if a == None or  b == None or a == self.root or b == self.root:
            return Node(None)

        ancestor_a = set()
        ancestor_b = set()
        while ancestor_a.intersection(ancestor_b) == set():
            try:
                ancestor_a.add(a.parent)
                a = a.parent
            except:
                pass
            try:
                ancestor_b.add(b.parent)
                b = b.parent
            except:
                pass

        res = list(ancestor_a.intersection(ancestor_b))
        if res:
            return res[0]
        return Node(None)
    

#driver code
#a = list(map(int, input().split()))
a = [5, 7, 3, 6, 8, 2, 9, 10]
tree = Tree(a)

print(tree.findLCA(3, 10).val)