Array Splitting
You cannot submit for this problem because the contest is ended. You can click "Open in Problem Set" to view this problem in normal mode.
Description
You are given an array $a_1, a_2, \dots, a_n$ and an integer $k$.
You are asked to divide this array into $k$ non-empty consecutive subarrays. Every element in the array should be included in exactly one subarray. Let $f(i)$ be the index of subarray the $i$-th element belongs to. Subarrays are numbered from left to right and from $1$ to $k$.
Let the cost of division be equal to $\sum\limits_{i=1}^{n} (a_i \cdot f(i))$. For example, if $a = [1, -2, -3, 4, -5, 6, -7]$ and we divide it into $3$ subbarays in the following way: $[1, -2, -3], [4, -5], [6, -7]$, then the cost of division is equal to $1 \cdot 1 - 2 \cdot 1 - 3 \cdot 1 + 4 \cdot 2 - 5 \cdot 2 + 6 \cdot 3 - 7 \cdot 3 = -9$.
Calculate the maximum cost you can obtain by dividing the array $a$ into $k$ non-empty consecutive subarrays.
The first line contains two integers $n$ and $k$ ($1 \le k \le n \le 3 \cdot 10^5$).
The second line contains $n$ integers $a_1, a_2, \dots, a_n$ ($ |a_i| \le 10^6$).
Print the maximum cost you can obtain by dividing the array $a$ into $k$ nonempty consecutive subarrays.
Input
The first line contains two integers $n$ and $k$ ($1 \le k \le n \le 3 \cdot 10^5$).
The second line contains $n$ integers $a_1, a_2, \dots, a_n$ ($ |a_i| \le 10^6$).
Output
Print the maximum cost you can obtain by dividing the array $a$ into $k$ nonempty consecutive subarrays.
5 2
-1 -2 5 -4 8
7 6
-3 0 -1 -2 -2 -4 -1
4 1
3 -1 6 0
15
-45
8
20240326集训
- Status
- Done
- Rule
- IOI
- Problem
- 7
- Start at
- 2024-3-26 19:00
- End at
- 2024-3-26 21:00
- Duration
- 2 hour(s)
- Host
-
SamuelXuch
- Partic.
- 14