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] = [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
```

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

```

Constraints:

• `1 <= n <= 2 * 104`
• `1 <= bookings.length <= 2 * 104`
• `bookings[i].length == 3`
• `1 <= firsti <= lasti <= n`
• `1 <= seatsi <= 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);
}
``````