1 #include<bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 ll d[500005],ans;
 5 bool vis[500005];
 6 int n,k,t,t1;
 7 int r[500005],l[500005];
 8 struct node{
 9     int id;
10     ll val;
11     node(ll Val,int Id){val=Val,id=Id;}
12     bool operator < (node a) const {
13         return val<a.val;
14     }
15 };
16 void del(int x){
17     l[x]=l[l[x]];
18     r[x]=r[r[x]];
19     r[l[x]]=l[r[x]]=x;
20 }
21 priority_queue<node> q;
22 int main(){
23     scanf("%d%d",&n,&k);
24     for(int i=1;i<=n;i++)scanf("%lld",&d[i]),l[i]=i-1,r[i]=i+1,q.push(node(d[i],i));
25     for(int i=1;i<=k;i++){
26         while(vis[q.top().id])
27          q.pop();
28         node tmp=q.top();q.pop();
29         if(tmp.val<0)break;
30         ans+=tmp.val;
31         vis[l[tmp.id]]=vis[r[tmp.id]]=1;
32         d[tmp.id]=d[l[tmp.id]]+d[r[tmp.id]]-d[tmp.id];
33         q.push(node(d[tmp.id],tmp.id));
34         del(tmp.id);
35     }
36     printf("%lld\n",ans);
37 } 

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll d[100005],ans;
bool vis[100005];
int n,k,t,t1;
int r[100005],l[100005];
struct node{ll val;int id;node(ll Val,int Id){val=Val,id=Id;}bool operator < (node a) const {return val>a.val; }
};
void del(int x){l[x]=l[l[x]];r[x]=r[r[x]];r[l[x]]=l[r[x]]=x;
}
priority_queue<node> q;
int main(){//freopen("a.in","r",stdin);int T;scanf("%d",&T); while(T--){ans=0;scanf("%d %d %d",&n,&k,&t);fill(vis+1,vis+n+1,0);for(int i=1;i<n;i++)scanf("%d",&t1),d[i]=t1-t,t=t1;d[0]=d[n]=2e9;for(int i=1;i<n;i++)l[i]=i-1,r[i]=i+1,q.push(node(d[i],i));for(int i=1;i<=k;i++){while(vis[q.top().id])q.pop();node tmp=q.top();q.pop();ans+=tmp.val;vis[l[tmp.id]]=vis[r[tmp.id]]=1;d[tmp.id]=d[l[tmp.id]]+d[r[tmp.id]]-d[tmp.id];q.push(node(d[tmp.id],tmp.id));del(tmp.id);}while(!q.empty())q.pop();printf("%lld\n",ans);}
}