裸dinic就跑过去了，哪用得着平面图最小割=最短路……
#include <iostream>
#include <cstring>
#include <cstdio>
#include <queue>
using namespace std;
int n, m, w, ss, tt, hea[1000005], cnt, lev[1000005], cur[1000005], maxFlow;
const int oo=0x3f3f3f3f;
queue<int> d;
struct Edge{
int too, nxt, val;
}edge[8000005];
void add_edge(int fro, int too, int val){
edge[cnt].nxt = hea[fro];
edge[cnt].too = too;
edge[cnt].val = val;
hea[fro] = cnt++;
}
void addEdge(int fro, int too, int val){
add_edge(fro, too, val);
add_edge(too, fro, val);//无向边一开始就能增广
}
int f(int a, int b){
return (a-1)*m+b;
}
bool bfs(){
memset(lev, 0, sizeof(lev));
lev[ss] = 1;
d.push(ss);
while(!d.empty()){
int x=d.front();
d.pop();
for(int i=hea[x]; i!=-1; i=edge[i].nxt){
int t=edge[i].too;
if(!lev[t] && edge[i].val>0){
lev[t] = lev[x] + 1;
d.push(t);
}
}
}
return lev[tt]!=0;
}
int dfs(int x, int lim){
if(x==tt) return lim;
int addFlow=0;
for(int &i=cur[x]; i!=-1; i=edge[i].nxt){
int t=edge[i].too;
if(lev[t]==lev[x]+1 && edge[i].val>0){
int tmp=dfs(t, min(lim-addFlow, edge[i].val));
edge[i].val -= tmp;
edge[i^1].val += tmp;
addFlow += tmp;
if(addFlow==lim) break;
}
}
return addFlow;
}
void dinic(){
while(bfs()){
for(int i=ss; i<=tt; i++) cur[i] = hea[i];
maxFlow += dfs(ss, oo);
}
}
int main(){
memset(hea, -1, sizeof(hea));
cin>>n>>m;
for(int i=1; i<=n; i++)
for(int j=1; j<m; j++){
scanf("%d", &w);
addEdge(f(i,j), f(i,j+1), w);
}
for(int i=1; i<n; i++)
for(int j=1; j<=m; j++){
scanf("%d", &w);
addEdge(f(i,j), f(i+1,j), w);
}
for(int i=1; i<n; i++)
for(int j=1; j<m; j++){
scanf("%d", &w);
addEdge(f(i,j), f(i+1,j+1), w);
}
ss = f(1,1); tt = f(n,m);
dinic();
cout<<maxFlow<<endl;
return 0;
}
平面图最短路：
#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdio>
using namespace std;
int n, m, ss, tt, uu, hea[2000005], cnt, dis[2000005], din;
bool vis[2000005];
const int oo=0x3f3f3f3f;
int p(int a, int b){
return (a-1)*(m-1)+b;
}
int q(int a, int b){
return p(a,b)+(n-1)*(m-1);
}
struct Edge{
int too, nxt, val;
}edge[8000005];
struct Node{
int idx, val;
}nd[9000005];
bool cmp(Node x, Node y){
return x.val>y.val;
}
void add_edge(int fro, int too, int val){
edge[++cnt].nxt = hea[fro];
edge[cnt].too = too;
edge[cnt].val = val;
hea[fro] = cnt;
}
void addEdge(int fro, int too, int val){
add_edge(fro, too, val);
add_edge(too, fro, val);
}
void dijk(){
memset(dis, 0x3f, sizeof(dis));
dis[ss] = 0;
nd[++din] = (Node){ss, 0};
while(din){
Node x=nd[1];
pop_heap(nd+1, nd+1+din, cmp);
din--;
if(vis[x.idx]) continue;
vis[x.idx] = true;
for(int i=hea[x.idx]; i; i=edge[i].nxt){
int t=edge[i].too;
if(!vis[t] && dis[t]>dis[x.idx]+edge[i].val){
dis[t] = dis[x.idx] + edge[i].val;
nd[++din] = (Node){t, dis[t]};
push_heap(nd+1, nd+1+din, cmp);
}
}
}
}
int main(){
cin>>n>>m;
if(n==1 || m==1){
int tmp=oo;
for(int i=1; i<=max(n,m); i++){
scanf("%d", &uu);
tmp = min(tmp, uu);
}
cout<<tmp<<endl;
return 0;
}
ss = 0; tt = q(n-1,m-1) + 1;
for(int i=1; i<=n; i++)
for(int j=1; j<m; j++){
scanf("%d", &uu);
if(i==1) addEdge(ss, p(i,j), uu);
else if(i==n) addEdge(q(i-1,j), tt, uu);
else addEdge(q(i-1,j), p(i,j), uu);
}
for(int i=1; i<n; i++)
for(int j=1; j<=m; j++){
scanf("%d", &uu);
if(j==1) addEdge(tt, q(i,j), uu);
else if(j==m) addEdge(p(i,j-1), ss, uu);
else addEdge(p(i,j-1), q(i,j), uu);
}
for(int i=1; i<n; i++)
for(int j=1; j<m; j++){
scanf("%d", &uu);
addEdge(p(i,j), q(i,j), uu);
}
dijk();
cout<<dis[tt]<<endl;
return 0;
}