729. My Calendar I

You are implementing a program to use as your calendar. We can add a new event if adding the event will not cause a double booking. A double booking happens when two events have some non-empty intersection (i.e., some moment is common to both events.). The event can be represented as a pair of integers start and end that represents a booking on the half-open interval [start, end), the range of real numbers x such that start <= x < end.

Implement the MyCalendar class: MyCalendar() Initializes the calendar object. boolean book(int start, int end) Returns true if the event can be added to the calendar successfully without causing a double booking. Otherwise, return false and do not add the event to the calendar.

Using balanced tree in C++

class MyCalendar {
private:
    map<int, int> tree;

public:
    MyCalendar() {}
    
    bool book(int start, int end) {
        auto nxt = tree.lower_bound(start);
        if (nxt != tree.end() && nxt->first < end)
            return false;
        if (nxt != tree.begin() && (--nxt)->second > start)
            return false;

        tree[start] = end;
        return true;
    }
};

Learning On the Way

Using balanced tree in C++