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#731 - My Calendar II

Problem Description

You are implementing a program to use as your calendar. We can add a new event if adding the event will not cause a triple booking.

A triple booking happens when three events have some non-empty intersection (i.e., some moment is common to all the three events.).

The event can be represented as a pair of integers startTime and endTime that represents a booking on the half-open interval [startTime, endTime), the range of real numbers x such that startTime <= x < endTime.

Implement the MyCalendarTwo class:

  • MyCalendarTwo() Initializes the calendar object.
  • boolean book(int startTime, int endTime) Returns true if the event can be added to the calendar successfully without causing a triple booking. Otherwise, return false and do not add the event to the calendar.

Solution

var MyCalendarTwo = function() {
  this.bookings = [];
  this.overlaps = [];
};

/**
 * @param {number} startTime
 * @param {number} endTime
 * @return {boolean}
 */
MyCalendarTwo.prototype.book = function(startTime, endTime) {
  for (const [start, end] of this.overlaps) {
    if (startTime < end && endTime > start) return false;
  }

  for (const [start, end] of this.bookings) {
    if (startTime < end && endTime > start) {
      this.overlaps.push([Math.max(start, startTime), Math.min(end, endTime)]);
    }
  }

  this.bookings.push([startTime, endTime]);
  return true;
};