bzoj 3144

3144

思路：

　　xxy；

代码：

#include <cstdio>

#include <cstring>

#include <iostream>

#include <algorithm>

using namespace std;

#define maxn 64005

#define INF 0x3f3f3f3f

const int dx[]={,-,,,};

const int dy[]={,,,,-};

int deep[maxn],head[maxn],E[maxn<<],V[maxn<<],F[maxn<<],ans;

int n,m,r,d,ai[][][],id[][][],s,t,cnt,que[maxn];

inline void in(int &now)

{

    char Cget=getchar();now=;

    while(Cget>''||Cget<'') Cget=getchar();

    while(Cget>=''&&Cget<='')

    {

        now=now*+Cget-'';

        Cget=getchar();

    }

}

inline void edge_add(int u,int v,int f)

{

    E[++cnt]=head[u],V[cnt]=v,F[cnt]=f,head[u]=cnt;

    E[++cnt]=head[v],V[cnt]=u,F[cnt]=,head[v]=cnt;

}

bool bfs()

{

    for(int i=s;i<=t;i++) deep[i]=-;

    deep[s]=,que[]=s;int h=,tail=,now;

    while(h<tail)

    {

        now=que[h++];

        for(int i=head[now];i;i=E[i])

            if(F[i]&&deep[V[i]]<)

            {

                deep[V[i]]=deep[now]+;

                if(V[i]==t) return true;

                que[tail++]=V[i];

            }

    }

    return false;

}

int flowing(int now,int flow)

{

    if(now==t||flow<=) return flow;

    int oldflow=,pos;

    for(int i=head[now];i;i=E[i])

    {

        if(deep[V[i]]!=deep[now]+||!F[i]) continue;

        pos=flowing(V[i],min(flow,F[i]));

        F[i]-=pos,F[i^]+=pos,flow-=pos,oldflow+=pos;

        if(!flow) return oldflow;

    }

    if(!oldflow) deep[now]=-;

    return oldflow;

}

int main()

{

    in(n),in(m),in(r),in(d);

    for(int i=;i<=r;i++)

        for(int v=;v<=n;v++)

            for(int e=;e<=m;e++) in(ai[i][v][e]),id[i][v][e]=++cnt;

    s=,t=cnt+,cnt=;

    for(int i=;i<=n;i++)

        for(int v=;v<=m;v++)

            edge_add(s,id[][i][v],ai[][i][v]),edge_add(id[r][i][v],t,INF);

    for(int z=;z<=r;z++)

    {

        for(int i=;i<=n;i++)

            for(int v=;v<=m;v++) edge_add(id[z-][i][v],id[z][i][v],ai[z][i][v]);

        if(z>d)

        {

            for(int i=;i<=n;i++)

                for(int v=;v<=m;v++)

                    for(int e=;e<=;e++)

                        if(i+dx[e]>&&i+dx[e]<=n&&v+dy[e]>&&v+dy[e]<=m)

                            edge_add(id[z][i][v],id[z-d][i+dx[e]][v+dy[e]],INF);

        }

    }

    while(bfs()) ans+=flowing(s,INF);

    printf("%d\n",ans);

    return ;

}