LCA with findPath

class Solution(object):
    def lowestCommonAncestor(self, root, p, q):
        def findPath(root, x, res):
            if not root: return False
            
            res.append(root.val)
            
            if root.val == x:
                return True
            
            if findPath(root.left, x, res) or findPath(root.right, x, res):
                return True
            res.pop()
            return False
                
            
        pres, qres = [],[]
        curr = root
        findPath(curr, p.val, pres)
        curr = root
        findPath(curr, q.val, qres)
        
        pi, qi = 0, 0
        while pi < len(pres) and qi < len(qres):
            p_elem, q_elem = pres[pi], qres[qi]
            if p_elem != q_elem:
                break
            pi += 1
            qi += 1
                
        return TreeNode(pres[pi - 1])