Node* Tree::LCA(Node* root, Node* n1, Node* n2) {
list<Node*> a1,a2;
while(n1 != NULL) {
a1.push_back(n1); // push n1
n1 = n1->parent;
}
while(n2 != NULL) {
a2.push_back(n2); // push n2
n2 = n2->parent;
}
Node* old; // create new node
while(!a1.empty() && !a2.empty() && a1.back() == a2.back()) {
old = a1.back(); // store the node before popping
a1.pop_back();
a2.pop_back();
}
if( a1.back() != a2.back()) {
// Node* rn = a1.back(); //not needed
cout << " LCA of r-U and r_v is " << old->index << endl; // changed
}
}
This might be helpful.