[BZOJ1001] [BJOI2006] 狼抓兔子

#include<iostream>
#include<cstring>
#include<cstdio>
using namespace std;
struct Item{int p,c,nxt;} it[8000005];
int dis[1000005],n,m,s,t,ans,tans,t1,t2,t3,ind,bus[1000005],pbus[1000005],cnt;
int qu[10000005];
struct Queue{
int head,tail;
inline void push(int x){
qu[++tail]=x;}
inline void pop(){
head++;}
inline int front(){
return qu[head];}
inline int size(){
return tail-head+1;}} q;

int dinic_bfs(){
q.push(s);
memset(dis,0xff,sizeof dis); dis[s]=1;
while(q.size()) {
int p=q.front(); q.pop();
for(register int i=bus[p]; i>=0; i=it[i].nxt)
if(dis[it[i].p]<0 && it[i].c>0)
q.push(it[i].p), dis[it[i].p]=dis[p]+1;}
return dis[t]>0;}

int dinic_dfs(int p,int lim){ cnt++;
int flow=0;
if(p==t) return lim;
for(int val,&i=pbus[p]; i>=0; i=it[i].nxt)
if(dis[it[i].p]==dis[p]+1 && it[i].c>0)
if(val=dinic_dfs(it[i].p,min(lim,it[i].c))){
it[i].c-=val, it[i^1].c+=val; flow+=val; lim-=val;
if(lim==0) break;}
return flow;}

inline void link(int p,int q,int w){
it[ind].nxt=-1;
it[ind].p=q; it[ind].c=w; it[ind].nxt=bus[p]; bus[p]=ind; ind++;}

inline void make(int p,int q,int w){
link(p,q,w);}

void dinic(){
while(dinic_bfs()) {
memcpy(pbus,bus,sizeof bus);
while(tans=dinic_dfs(s,1e+9)) ans+=tans;}}

int main(){
memset(bus,0xff,sizeof bus);
q.head=1;q.tail=0;
scanf("%d%d",&n,&m);
for(int i=1;i<=n;i++)
for(int j=1;j<=m-1;j++)
scanf("%d",&t1),
make(i*m-m+j,i*m-m+j+1,t1),
make(i*m-m+j+1,i*m-m+j,t1);
for(int i=1;i<=n-1;i++)
for(int j=1;j<=m;j++)
scanf("%d",&t1),
make(i*m-m+j,i*m+j,t1),
make(i*m+j,i*m-m+j,t1);
for(int i=1;i<=n-1;i++)
for(int j=1;j<=m-1;j++)
scanf("%d",&t1),
make(i*m-m+j,i*m+j+1,t1),
make(i*m+j+1,i*m-m+j,t1);
s=1; t=n*m;
dinic();
printf("%d\n",ans);
}