1650. Lowest Common Ancestor of a Binary Tree III

/*
// Definition for a Node.
class Node {
    public int val;
    public Node left;
    public Node right;
    public Node parent;
};
*/

class Solution {
    public Node lowestCommonAncestor(Node p, Node q) {
        Node p1 = p;
        Node q1 = q;
        while (p1 != q1) {
            p1 = p1 == null ? q : p1.parent;
            q1 = q1 == null ? p : q1.parent;
        }
        return p1;
    }
}