1109. Corporate Flight Bookings 

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class Solution {
    public int[] corpFlightBookings(int[][] bookings, int n) {
        int[] diff = new int[n];

        for (int[] book : bookings) {
            int from = book[0] - 1, to = book[1] - 1, count = book[2]; // [from, to]
            diff[from] += count;
            if (to + 1 < diff.length) {
                diff[to + 1] -= count;
            }
        }

        int[] res = new int[n];
        res[0] = diff[0];
        for (int i = 1; i < res.length; i++) {
            res[i] = res[i - 1] + diff[i];
        }
        return res;
    }
}

References

1109. Corporate Flight Bookings