// assume start < end
// assume s <= start < end <= e
void insert(int start, int end) {
if (s == start && e == end) {
inserted = true;
return;
}
if (end <= p) {
if (l == nullptr) l = new range(s, p);
l->insert(start, end);
}
else if (start < p && end > p) {
if (l == nullptr) l = new range(s, p);
if (r == nullptr) r = new range(p, e);
l->insert(start, p);
r->insert(p, end);
}
else if (start >= p) {
if (r == nullptr) r = new range(p, e);
r->insert(start, end);
}
}
bool book(int start, int end) {
if (r.conflict(start, end))
return false;
r.insert(start, end);
return true;
}