学步园

http://www.lydsy.com/JudgeOnline/problem.php?id=3774

tm这最小割能考到这么变态是一种境界

//#define _TEST _TEST
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <iostream>
#include <cmath>
#include <algorithm>
using namespace std;
/************************************************
Code By willinglive    Blog:http://willinglive.cf
************************************************/
#define rep(i,l,r) for(int i=(l),___t=(r);i<=___t;i++)
#define per(i,r,l) for(int i=(r),___t=(l);i>=___t;i--)
#define MS(arr,x) memset(arr,x,sizeof(arr))
#define LL long long
#define INE(i,u,e) for(int i=head[u];~i;i=e[i].next)
inline const int read()
{int r=0,k=1;char c=getchar();for(;c<'0'||c>'9';c=getchar())if(c=='-')k=-1;
for(;c>='0'&&c<='9';c=getchar())r=r*10+c-'0';return k*r;}
/////////////////////////////////////////////////
const int inf=0x3f3f3f3f;
const int N=6000;
const int M=8*N;
int n,m;
int a[51][51],b[51][51];
struct edge{int v,flow,cap,next;}e[M];
int head[N],k;
int S,T;
int cur[N],d[N],q[N];  
int di[]={0,0,1,-1};
int dj[]={1,-1,0,0};
/////////////////////////////////////////////////
inline int enc(int x,int y,bool b){return ((x-1)*m+y)<<1|b;}
void adde(int u,int v,int f){e[k].v=v;e[k].flow=0;e[k].cap=f;e[k].next=head[u];head[u]=k++;}  
void ins(int u,int v,int f1,int f2){adde(u,v,f1);adde(v,u,f2);}  
inline int F(int i){return e[i].cap-e[i].flow;}  
bool bfs()  
{  
    MS(d,-1); d[q[0]=S]=0; memcpy(cur,head,sizeof(cur));  
    for(int u,v,l=0,r=1;l<r;)  
    {  
        u=q[l++];  
        INE(i,u,e) if(F(i)&&d[v=e[i].v]==-1)  
        {  
            q[r++]=v; d[v]=d[u]+1;  
            if(v==T) return 1;  
        }  
    }  
    return 0;  
}  
int dfs(int u,int a)  
{  
    if(u==T||a==0) return a;  
    for(int &i=cur[u];~i;i=e[i].next) if(F(i)&&d[e[i].v]==d[u]+1)  
    {  
        if(int t=dfs(e[i].v,min(a,F(i))))  
        {  
            e[i].flow+=t; e[i^1].flow-=t;  
            return t;  
        }  
    }  
    return 0;  
}  
int dinic()  
{  
    int f=0;  
    while(bfs()) while(int t=dfs(S,inf)) f+=t;  
    return f;  
}  
/////////////////////////////////////////////////
void input()
{
	MS(head,-1);
    n=read(); m=read();
    rep(i,1,n) rep(j,1,m) a[i][j]=read();
    rep(i,1,n) rep(j,1,m) b[i][j]=read();
}
void solve()
{
	S=enc(n,m,1)+1; T=S+1;
	rep(i,1,n) rep(j,1,m)
	{
		if((i+j)&1)
		{
			ins(S,enc(i,j,0),a[i][j],0);
			ins(enc(i,j,0),enc(i,j,1),b[i][j],0);
		}
		else
		{
			ins(enc(i,j,0),T,a[i][j],0);
			ins(enc(i,j,1),enc(i,j,0),b[i][j],0);
		}
		rep(k,0,3)
		{
			int ni=i+di[k],nj=j+dj[k];
			if(ni<1||ni>n||nj<1||nj>m) continue;
			if((i+j)&1) ins(enc(i,j,1),enc(ni,nj,0),inf,0);
			else ins(enc(ni,nj,0),enc(i,j,1),inf,0);
		}
	}
	int s=0;
	rep(i,1,n) rep(j,1,m) s+=b[i][j];
	cout<<s-dinic()<<endl;
}
/////////////////////////////////////////////////
int main()
{
    #ifndef _TEST
    freopen("std.in","r",stdin); freopen("std.out","w",stdout);
    #endif
    input(),solve();
    return 0;
}