There are `n`

flights that are labeled from `1`

to `n`

.

You are given an array of flight bookings `bookings`

, where `bookings[i] = [first`

represents a booking for flights _{i}, last_{i}, seats_{i}]`first`

through _{i}`last`

(_{i}**inclusive**) with `seats`

seats reserved for _{i}**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 = 5Output:[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 = 2Output:[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 * 10`

^{4}`1 <= bookings.length <= 2 * 10`

^{4}`bookings[i].length == 3`

`1 <= first`

_{i}<= last_{i}<= n`1 <= seats`

_{i}<= 10^{4}

```
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);
}
```