hdu 6058 Kanade's sum (多校3)

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<string>
#include<algorithm>
#include<iostream>
#include<queue>
#include<map>
#include<cmath>
#include<set>
#include<stack>
#define ll long long
#define pb push_back
#define max(x,y) ((x)>(y)?(x):(y))
#define min(x,y) ((x)>(y)?(y):(x))
#define cls(name,x) memset(name,x,sizeof(name))//0或-1
#define fs first
#define sc second
#define mp make_pair
#define L(x) (1<<x)
#define next Next
using namespace std;
const int inf=1e9+10;
const ll llinf=1e16+10;
const int maxn=5e5+10;
const int maxm=2e5+10;
const int mod=1e9+7;
int n,k;
int A[maxn],next[maxn],pre[maxn];
int idx[maxn];
bool cmp(const int &a,const int &b)
{
    return A[a]<A[b];
}
void del(int pos)
{
    if(next[pos]!=-1)
    pre[next[pos]]=pre[pos];
    if(pre[pos]!=-1)
    next[pre[pos]]=next[pos];
}
int func(int i,int c[],int op)
{
    if(c[i]==0) return 0;
    if(op==1)
    {
        if(c[i+1]!=0)
        return c[i] - (c[i+1]+1) + 1;
        else return c[i] - 1 + 1;
    }
    if(op==2)
    {
        if(c[i+1]!=0)
            return (c[i+1]-1) - c[i] + 1;
        else return n - c[i] + 1;
    }
}
ll solve(int pos)
{
    int c1[100],c2[100];
    cls(c1,0); cls(c2,0);
    int t=1;
    c1[0]=pos;
    for(int i=pre[pos];i!=-1&&t<=k;i=pre[i])
        c1[t++]=i;
    t=1;
    c2[0]=pos;
    for(int i=next[pos];i!=-1&t<=k;i=next[i])
        c2[t++]=i;
    int c=0;
    for(int i=0;i<=k-1;i++)
        c+=func(i,c1,1)*func(k-1-i,c2,2);
    return (ll)c*A[pos];
}
int main()
{
    //freopen("in.txt","r",stdin);
    int ncas;
    scanf("%d",&ncas);
    while(ncas--)
    {
        scanf("%d %d",&n,&k);
        for(int i=1;i<=n;i++)
        {
            scanf("%d",&A[i]);
            if(i==1) pre[i]=-1;
            else pre[i]=i-1;
            if(i==n) next[i]=-1;
            else next[i]=i+1;
            idx[i]=i;
        }
        sort(idx+1,idx+n+1,cmp);
        ll ans=0;
        for(int i=1;i<=n;i++)
        {
            int pos=idx[i];
            ans+=solve(pos);
            del(pos);
        }
        printf("%lld
",ans);
    }
    return 0;
}