10537: ABC117 —— C - Streamline
[Creator : ]
Description
We will play a one-player game using a number line and $N$ pieces.
First, we place each of these pieces at some integer coordinate.
Here, multiple pieces can be placed at the same coordinate.
Our objective is to visit all of the $M$ coordinates $X_1, X_2, ..., X_M$ with these pieces, by repeating the following move:
Move: Choose a piece and let $x$ be its coordinate. Put that piece at coordinate $x+1$ or $x-1$.
Note that the coordinates where we initially place the pieces are already regarded as visited.
Find the minimum number of moves required to achieve the objective.
First, we place each of these pieces at some integer coordinate.
Here, multiple pieces can be placed at the same coordinate.
Our ob
Move: Choose a piece and let $x$ be its coordinate. Put that piece at coordinate $x+1$ or $x-1$.
Note that the coordinates where we initially place the pieces are already regarded as visited.
Find the minimum number of moves required to achieve the ob
Input
Input is given from Standard Input in the following format:
```
$N$ $M$
$X_1$ $X_2$ $...$ $X_M$
```
```
$N$ $M$
$X_1$ $X_2$ $...$ $X_M$
```
Output
Find the minimum number of moves required to achieve the objective.
Constraints
- All values in input are integers.
- $1 \leq N \leq 10^5$
- $1 \leq M \leq 10^5$
- $-10^5 \leq X_i \leq 10^5$
- $X_1, X_2, ..., X_M$ are all different.
- $1 \leq N \leq 10^5$
- $1 \leq M \leq 10^5$
- $-10^5 \leq X_i \leq 10^5$
- $X_1, X_2, ..., X_M$ are all different.
Sample 1 Input
2 5
10 12 1 2 14
Sample 1 Output
5
The objective can be achieved in five moves as follows, and this is the minimum number of moves required.
- Initially, put the two pieces at coordinates 1 and 10.
- Move the piece at coordinate 1 to 2.
- Move the piece at coordinate 10 to 11.
- Move the piece at coordinate 11 to 12.
- Move the piece at coordinate 12 to 13.
- Move the piece at coordinate 13 to 14.
Sample 2 Input
3 7
-10 -3 0 9 -100 2 17
Sample 2 Output
19
Sample 3 Input
100 1
-100000
Sample 3 Output
0