NODE *
Tree_Successor (
NODE *x //don't need the root: find in the subtree of x
)
{
//return the smallest node of those larger than x.
NODE *suc;
NODE *y;
if (x->right) {
suc = Tree_Minimum (x->right);
} else {
//look upward
y = x->p;
while (y && x == y->right) {
//y < x
//traverse until y > x (x is left child)
x = y;
y = y->p;
}
suc = y;
}
return suc;
}
rb_vertex<T>* Tree_Successor(rb_vertex<T>* subject) {
if (subject->get_right_child() != 0) {
return Tree_Minimum(subject);
}
rb_vertex<T>* temp = subject->get_parent();
while(temp != 0 and subject == temp->get_right_child()) {
subject = temp;
temp = temp->get_parent();
}
return temp;
}
