- Difficulty: Medium
- Tags: LeetCode, Medium, Array, Prefix Sum, leetcode-1109, O(n), O(1), Line Sweep
Problem
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