# https://leetcode.com/problems/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.


Example 1:
Input
["MyCalendar", "book", "book", "book"]
[[], [10, 20], [15, 25], [20, 30]]
Output
[null, true, false, true]
Explanation
MyCalendar myCalendar = new MyCalendar();
myCalendar.book(10, 20); // return True
myCalendar.book(15, 25); // return False, It can not be booked because time 15 is already booked by another event.
myCalendar.book(20, 30); // return True, The event can be booked, as the first event takes every time less than 20, but not including 20.

Constraints:
0 <= start < end <= 109
At most 1000 calls will be made to book.
"""
from sortedcontainers import SortedList


# brute force: O(N^2)
class MyCalendar:
    def __init__(self):
        self.calendars = []

    def book(self, start: int, end: int) -> bool:
        for s, e in self.calendars:
            if start < e and end > s:
                return False
        self.calendars.append([start, end])
        return True


class MyCalendar:
    def __init__(self):
        self.l = SortedList()
        self.r = SortedList()

    def book(self, start: int, end: int) -> bool:
        idx = self.l.bisect_left(end)
        if idx and self.r[idx - 1] > start:
            return False
        self.l.add(start)
        self.r.add(end)
        return True
