1109. Corporate Flight Bookings

Medium

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There are n flights that are labeled from 1 to n.

You are given an array of flight bookings bookings, where bookings[i] = [firsti, lasti, seatsi] represents a booking for flights firsti through lasti (inclusive) with seatsi seats reserved for each flight in the range.

Return an array answer of length n, where answer[i] is the total number of seats reserved for flight i.

Example 1:

Input: bookings = [[1,2,10],[2,3,20],[2,5,25]], n = 5
Output: [10,55,45,25,25]
Explanation:
Flight labels:        1   2   3   4   5
Booking 1 reserved:  10  10
Booking 2 reserved:      20  20
Booking 3 reserved:      25  25  25  25
Total seats:         10  55  45  25  25
Hence, answer = [10,55,45,25,25]

Example 2:

Input: bookings = [[1,2,10],[2,2,15]], n = 2
Output: [10,25]
Explanation:
Flight labels:        1   2
Booking 1 reserved:  10  10
Booking 2 reserved:      15
Total seats:         10  25
Hence, answer = [10,25]

Constraints:

• 1 <= n <= 2 * 104

• 1 <= bookings.length <= 2 * 104

• bookings[i].length == 3

• 1 <= firsti <= lasti <= n

• 1 <= seatsi <= 104

class Solution:
    def corpFlightBookings(self, bookings: List[List[int]], n: int) -> List[int]:
        l = [0]*(n+1)
        for first, last, seats in bookings:
            l[first-1] += seats
            l[last] -= seats
        for index in range(1, n):
            l[index] += l[index-1]
        return l[:n]