【USACO 1.3】Barn Repair

贪心，去掉最大的min（m，c）-1个间隔

/*******************************************
  TASK: barn1
  LANG: C++
  Created Time: 2016/9/9 14:36:17
 *********************************/

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int a[],d[];
int main(){
    freopen("barn1.in","r",stdin);
    freopen("barn1.out","w",stdout);
    int m,s,c;
    cin>>m>>s>>c;
    for(int i=;i<c;i++)cin>>a[i];
    sort(a,a+c);
    int ans=a[c-]-a[]+;
    for(int i=;i<c;i++)
        d[i]=a[i]-a[i-]-;
    sort(d+,d+c);
    for(int i=;i<min(m,c);i++)
        ans-=d[c-i];
    cout<<ans<<endl;

}