把每个点拆成 x y z
对于第 i 个点，x->y是表示流入的，y->z是表示流出的。
#include <iostream>
#include <cstring>
#include <cstdio>
#include <queue>
using namespace std;
int n, m, ss, tt, hea[1305], cnt, minCost, pre[1305], dis[1305], maxFlow, qaq, qwq;
const int oo=0x3f3f3f3f;
const int dx[]={0, 1, 1, 1, 0, -1, -1, -1, 0};
const int dy[]={0, 1, 0, -1, -1, -1, 0, 1, 1};
bool vis[1305];
char cs[25][25], js[25][25], xz[25][25];
struct Edge{
int too, nxt, val, cst;
}edge[9005];
queue<int> d;
int x(int i, int j){
return (i-1)*m+j;
}
int y(int i, int j){
return (i-1)*m+j+n*m;
}
int z(int i, int j){
return (i-1)*m+j+2*n*m;
}
void add_edge(int fro, int too, int val, int cst){
edge[cnt].nxt = hea[fro];
edge[cnt].too = too;
edge[cnt].val = val;;
edge[cnt].cst = cst;
hea[fro] = cnt++;
}
void addEdge(int fro, int too, int val, int cst){
add_edge(fro, too, val, cst);
add_edge(too, fro, 0, -cst);
}
int bfs(){
memset(dis, 0x3f, sizeof(dis));
memset(pre, -1, sizeof(pre));
dis[ss] = 0;
vis[ss] = true;
d.push(ss);
while(!d.empty()){
int x=d.front();
d.pop();
vis[x] = false;
for(int i=hea[x]; i!=-1; i=edge[i].nxt){
int t=edge[i].too;
if(dis[t]>dis[x]+edge[i].cst && edge[i].val>0){
dis[t] = dis[x] + edge[i].cst;
pre[t] = i;
if(!vis[t]){
vis[t] = true;
d.push(t);
}
}
}
}
return dis[tt]!=oo;
}
void dinic(){
while(bfs()){
int tmp=oo;
for(int i=pre[tt]; i!=-1; i=pre[edge[i^1].too])
tmp = min(tmp, edge[i].val);
for(int i=pre[tt]; i!=-1; i=pre[edge[i^1].too]){
edge[i].val -= tmp;
edge[i^1].val += tmp;
minCost += tmp * edge[i].cst;
}
maxFlow += tmp;
}
}
int main(){
memset(hea, -1, sizeof(hea));
cin>>n>>m;
for(int i=1; i<=n; i++) scanf("%s", cs[i]+1);
for(int i=1; i<=n; i++) scanf("%s", js[i]+1);
for(int i=1; i<=n; i++) scanf("%s", xz[i]+1);
ss = 0; tt = n * m * 3 + 1;
for(int i=1; i<=n; i++)
for(int j=1; j<=m; j++){
if(cs[i][j]=='1' && js[i][j]=='0'){
qaq++;
addEdge(ss, y(i,j), 1, 0);
addEdge(x(i,j), y(i,j), (xz[i][j]-'0')/2, 0);
addEdge(y(i,j), z(i,j), (xz[i][j]-'0'+1)/2, 0);//原来黑而后来白，给流出的分多一点容量比较好
}
else if(cs[i][j]=='0' && js[i][j]=='1'){
qwq++;
addEdge(y(i,j), tt, 1, 0);
addEdge(x(i,j), y(i,j), (xz[i][j]-'0'+1)/2, 0);
addEdge(y(i,j), z(i,j), (xz[i][j]-'0')/2, 0);
}
else{
addEdge(x(i,j), y(i,j), (xz[i][j]-'0')/2, 0);
addEdge(y(i,j), z(i,j), (xz[i][j]-'0')/2, 0);
}
for(int k=1; k<=8; k++){
int kx=i+dx[k];
int ky=j+dy[k];
if(kx<1 || kx>n || ky<1 || ky>m) continue;
addEdge(z(i,j), x(kx,ky), oo, 1);
}
}
dinic();
if(qaq==qwq && maxFlow==qwq) cout<<minCost<<endl;
else cout<<"-1"<<endl;
return 0;
}