bzoj1001（网络流，最小割）狼抓兔子

第一个博客，刷道水题吧。。。最大流=最小割

#include<cstdio>
#include<cctype>
#include<cstring>
#include<vector>
#include<algorithm>
#include<iostream>
using namespace std;
const int N=1000005,M=6000005;
const int oo=2e9+7;
int a
,b
,nedge,son
,tot,n,m,gap
,d
,que
,l,r;
struct edge{
int nextt,ed,di;
}e[M];
inline int	read()//²»¹ÜÊÇÕý¸ºÊý£¬¶¼¿ÉÒÔ
{
int x = 0; char ch = getchar(); bool positive = 1;
for (; !isdigit(ch); ch = getchar())	if (ch == '-')	positive = 0;
for (; isdigit(ch); ch = getchar())	x = x * 10 + ch - '0';
return positive ? x : -x;
}
inline void write(int a){
if(a>=10)write(a/10);
putchar('0'+a%10);
}
inline void writeln(int a){
write(a); puts("");
}
inline void aedge(int a,int b,int c){
e[++nedge].nextt=son[a];
son[a]=nedge;
e[nedge].ed=b;
e[nedge].di=c;
}
inline void ycl(int s,int t) {
memset(gap,0,sizeof gap),memset(d,0,sizeof d),++gap[d[t]=1];
que[l=r=1]=t;
while(l<=r){
int k=que[l++];
for (int i=son[k];i;i=e[i].nextt)if(!d[e[i].ed])++gap[d[e[i].ed]=d[k]+1],que[++r]=e[i].ed;
}
}
inline int aug(int x,int s,int t,int mmin) {
if(x==t)return mmin;
int flow=0;
for(int i=son[x];i;i=e[i].nextt)if(d[x]==d[e[i].ed]+1){
int tmp=aug(e[i].ed,s,t,min(mmin,e[i].di));
flow+=tmp;mmin-=tmp;e[i].di-=tmp;e[((i-1)^1)+1].di+=tmp;
if(!mmin)return flow;
}
if(!(--gap[d[x]]))d[s]=n+1; ++gap[++d[x]];
return flow;
}
inline int maxflow(int s,int t) {
ycl(s,t); int ans=aug(s,s,t,oo);
while(d[s]<=n)ans+=aug(s,s,t,oo);
return ans;
}
int main(){
int nn=read(),mm=read(); n=nn*mm;
for(int i=1;i<=nn;i++)for(int j=1;j<mm;j++){
int s1=read(); aedge((i-1)*mm+j,(i-1)*mm+j+1,s1); aedge((i-1)*mm+j+1,(i-1)*mm+j,s1);
}
for(int i=1;i<nn;i++)for(int j=1;j<=mm;j++){
int s1=read(); aedge((i-1)*mm+j,i*mm+j,s1); aedge(i*mm+j,(i-1)*mm+j,s1);
}
for(int i=1;i<nn;i++)for(int j=1;j<mm;j++){
int s1=read(); aedge((i-1)*mm+j,i*mm+j+1,s1); aedge(i*mm+j+1,(i-1)*mm+j,s1);
}
cout<<maxflow(1,n)<<endl;
}