SPOJ BOXES

#include <iostream>
#include <cstring>
#include <cstdio>
#define maxn 1010
#define maxm 55555
using namespace std;

const int inf=maxn;
int to[maxm],cap[maxm],cost[maxm],next[maxm],first[maxn],edge;
int d[maxn],num[maxn],from[maxn],tag[maxn],TAG=222;
int Q[maxm],bot,top;
int n,m,s,t,ans,T,a[maxn];

void _init()
{
    edge=-1,s=0,t=n+1,ans=0;
    for (int i=s; i<=t; i++) first[i]=-1;
}

void addedge(int U,int V,int W,int C)
{
    edge++;
    to[edge]=V,cap[edge]=W,cost[edge]=C,next[edge]=first[U],first[U]=edge;
    edge++;
    to[edge]=U,cap[edge]=0,cost[edge]=-C,next[edge]=first[V],first[V]=edge;
}

bool bfs()
{
    Q[bot=top=1]=s,d[s]=0,num[s]=inf,from[s]=-1,tag[s]=++TAG;
    while (bot<=top){
        int cur=Q[bot++];
        for (int i=first[cur]; i!=-1; i=next[i])
            if (cap[i]>0 && (tag[to[i]]!=TAG || d[cur]+cost[i]<d[to[i]])){
                d[to[i]]=d[cur]+cost[i];
                tag[to[i]]=TAG,
                num[to[i]]=min(num[cur],cap[i]);
                Q[++top]=to[i];
                from[to[i]]=i;
            }
    }
    if (tag[t]!=TAG || num[t]<=0) return false;
    ans+=num[t]*d[t];
    for (int i=t; from[i]!=-1; i=to[from[i]^1])
        cap[from[i]]-=num[t],cap[from[i]^1]+=num[t];
    return true;
}

int main()
{
    scanf("%d",&T);
    while (T--)
    {
        scanf("%d",&n);
        _init();
        for (int i=1; i<=n; i++) {
            scanf("%d",&a[i]);
            addedge(s,i,a[i],0);
            addedge(i,t,1,0);
            if (i<n) addedge(i,i+1,inf,1);
            if (i>1) addedge(i,i-1,inf,1);
        }
        addedge(1,n,inf,1);
        addedge(n,1,inf,1);
        while (bfs()) ;
        printf("%d\n",ans);
    }
    return 0;
}