Corporate Flight Bookings

Description

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

Code

same logic as Car Pooling。

Time Complexity: $O(n)$, Space Complexity: $O(n)$

class Solution {
public:
    vector<int> corpFlightBookings(vector<vector<int>>& bookings, int n) {
        vector<int> reserved(n, 0);
        for(auto& book: bookings) {
            reserved[book[0] - 1] += book[2];
            if(book[1] != n)
                reserved[book[1]] -= book[2];
        }
        vector<int> res;
        int count = 0;
        for(auto& r: reserved) {
            count += r;
            res.push_back(count);
        }
        return res;
    }
};

Source

• Corporate Flight Bookings - LeetCode