Calender Matching.py

"""
   Calendar Matching ♡
    Imagine that you want to schedule a meeting of a certain duration with a co-worker. You have access to your calendar
    and your co-worker's calendar (both of which contain
    your respective meetings for the day, in the form of [startTime, endTime] ), as well as both of your daily bounds
    (i.e., the earliest and latest times at which you're
    available for meetings every day, in the form of [earliestTime, latestTime] ).
    Write a function that takes in your calendar, your daily bounds, your co-worker's calendar, your co-worker's daily
    bounds, and the duration of the meeting that you want to
    schedule, and that returns a list of all the time blocks (in the form of [startTime, endTime] ) during which you
    could schedule the meeting ordered from earliest time block to latest.

    Note that times will be given and should be returned in military time. For example: 8:30 , 9:01 , and 23:56 .
    Also note that the given calendar times will be sorted by start time in ascending order, as you would expect them
    to appear in a calendar application like Google Calendar.

     Sample Input
        calendar1 = [['9:00', '10:30'], ['12:00', '13:00'], ['16:00', '18:00']]
        dailyBounds1 = ['9:00', '20:00']
        calendar2 = [['10:00', '11:30'], ['12:30', '14:30'], ['14:30', '15:00'], ['16:00', '17:00']]
        dailyBounds2 = ['10:00', '18:30']
        meetingDuration = 30

     Sample Output
        [['11:30', '12:00'], ['15:00', '16:00'], ['18:00', '18:30']]

"""

# SOLUTION 1

# 0(ci + c2) tine | (ci + c2) space - Where di and c2 are the respective numbers of meetings in calendar1 and calendar2
def calendarMatching(calendar1, dailyBounds1, calendar2, dailyBounds2, meetingDuration):
    updatedCalendar1 = updateCalendar(calendar1, dailyBounds1)
    updatedCalendar2 = updateCalendar(calendar2, dailyBounds2)
    mergedCalendar = mergeCalendars(updatedCalendar1, updatedCalendar2)
    flattenedCalendar = flattenCalendar (mergedCalendar)
    return getMatchingAvailabilities(flattenedCalendar, meetingDuration)

def updateCalendar(calendar, dailyBounds):
    updatedCalendar = calendar[:]
    updatedCalendar.insert(0, ["0:00", dailyBounds[0]])
    updatedCalendar.append([dailyBounds [1], "23:59"])
    return list(map(lambda m : [timeToMinutes (m[0]), timeToMinutes(m[1])], updatedCalendar))

def mergeCalendars(calendar1, calendar2):
    merged = []
    i, j = 0,0
    while i < len(calendar1) and j < len(calendar2):
        meeting1, meeting2 = calendar1[i], calendar2[j]
        if meeting1[0] < meeting2[0]:
            merged.append(meeting1)
            i += 1
        else:
            merged.append(meeting2)
            j += 1
    while i < len(calendar1):
        merged.append(calendar1[i])
        i += 1
    while j < len(calendar2):
        merged.append(calendar2[j])
        j += 1
    return merged

def flattenCalendar(calendar):
    flattened = [calendar[0][:]]
    for i in range(1, len(calendar)):
        currentMeeting = calendar[i]
        previousMeeting = flattened[-1]
        currentStart, currentEnd = currentMeeting
        previousStart, previousEnd = previousMeeting
        if previousEnd >= currentStart:
            newPreviousMeeting = [previousStart, max(previousEnd, currentEnd)]
            flattened[- 1] = newPreviousMeeting

        else:
            flattened.append(currentMeeting[:])
    return flattened

def getMatchingAvailabilities(calendar, meetingDuration):
    matchingAvailabilities = []
    for i in range(1, len(calendar)):
        start = calendar[i - 1][1]
        end = calendar[i][0]
        availabilityDuration = end - start
        if availabilityDuration >= meetingDuration:
            matchingAvailabilities.append([start, end])
    return list(map(lambda m: [minutesToTime(m[0]), minutesToTime(m[1])], matchingAvailabilities))

def timeToMinutes(time):
    hours, minutes = list(map(int, time.split(":")))
    return hours * 60 + minutes

def minutesToTime(minutes):
    hours = minutes // 60
    mins = minutes % 60
    hoursString = str(hours)
    minuteString = "0" + str(mins) if mins < 10 else str(mins)
    return hoursString + ":" + minuteString