Hotel Bookings Possible

• Time : $O(nlogn)$
• Space : $O(n)$

bool Solution::hotel(vector<int> &arrive, vector<int> &depart, int K) {
    priority_queue<int,vector<int>,greater<int>> q;
    vector<pair<int,int>> A;
    for(int i = 0; i < arrive.size(); i++) A.push_back({arrive[i], depart[i]});
    sort(begin(A), end(A));
    for(auto [a,d] : A) {
        while(q.size() and q.top() < a) q.pop();
        q.push(d);
        if(q.size() > K) return false;
    }
    return true;
}