Rust Gym Leetcode 1109 Corporate Flight Bookings Rust Solution

1109. Corporate Flight Bookings

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

You are given an array of flight bookings bookings, where bookings[i] = [first_i, last_i, seats_i] represents a booking for flights first_i through last_i (inclusive) with seats_i 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 <= first_i <= last_i <= n
1 <= seats_i <= 10⁴

1109. Corporate Flight Bookings

struct Solution;

impl Solution {
    fn corp_flight_bookings(bookings: Vec<Vec<i32>>, n: i32) -> Vec<i32> {
        let n = n as usize;
        let mut res = vec![0; n];
        for booking in bookings {
            let start = (booking[0] - 1) as usize;
            let end = booking[1] as usize;
            res[start] += booking[2];
            if end < n {
                res[end] -= booking[2];
            }
        }
        let mut prev = 0;
        for i in 0..n {
            prev += res[i];
            res[i] = prev;
        }
        res
    }
}

#[test]
fn test() {
    let bookings = vec_vec_i32![[1, 2, 10], [2, 3, 20], [2, 5, 25]];
    let n = 5;
    let res = vec![10, 55, 45, 25, 25];
    assert_eq!(Solution::corp_flight_bookings(bookings, n), res);
}