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| #include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int INF=0x3f3f3f3f;
const int MAXN=100005;
int N,M,S,T;
ll sum;
int nx[]={0,1,0,-1};
int ny[]={1,0,-1,0};
struct Edge{
int v,w,nxt;
}mem[MAXN];
int head[MAXN],cnt=1;
inline void AddEdge(int u,int v,int w){
mem[++cnt].w=w;
mem[cnt].v=v;
mem[cnt].nxt=head[u];
head[u]=cnt;
}
int d[MAXN];
bool vis[MAXN];
inline bool bfs(){
memset(vis,0,sizeof(vis));
vis[S]=1;d[S]=0;
queue<int> q;
q.push(S);
while(q.size()){
int u=q.front();q.pop();
for(register int i=head[u];i;i=mem[i].nxt){
int v=mem[i].v,w=mem[i].w;
if(vis[v]||(w==0)) continue;
vis[v]=1;d[v]=d[u]+1;
q.push(v);
}
}
return vis[T];
}
inline int dfs(int u,int flow){
if(u==T) return flow;
int rflow;
for(register int i=head[u];i;i=mem[i].nxt){
int v=mem[i].v,w=mem[i].w;
if(w==0||d[u]+1!=d[v]) continue;
if(rflow=dfs(v,min(flow,w))){
mem[i].w-=rflow;
mem[i^1].w+=rflow;
return rflow;
}
}
return 0;
}
inline int Dinic(){
int maxflow=0,lowflow;
while(bfs()){
while(lowflow=dfs(S,INF)) maxflow+=lowflow;
}
return maxflow;
}
int main(){
scanf("%d%d",&M,&N);
S=0,T=M*N+1;
for(register int i=1;i<=M;++i){
for(register int j=1;j<=N;++j){
int w;
scanf("%d",&w);
sum+=w;
if((i+j)&1){
AddEdge(S,(i-1)*N+j,w);
AddEdge((i-1)*N+j,S,INF);
for(register int k=0;k<=3;++k){
int tx=i+nx[k],ty=j+ny[k];
if(tx<1||tx>M||ty<1||ty>N) continue;
AddEdge((i-1)*N+j,(tx-1)*N+ty,INF);
AddEdge((tx-1)*N+ty,(i-1)*N+j,0);
}
}
else{
AddEdge((i-1)*N+j,T,w);
AddEdge(T,(i-1)*N+j,INF);
}
}
}
printf("%lld",sum-Dinic());
return 0;
}
|
