nefu473最大流模板简单应用

#include <iostream>
#include <cstdio>
using namespace std;
const int oo=1e9;
const int mm=111111;
const int mn=999;
int node,src,dest,edge;
int ver[mm],flow[mm],next[mm];
int head[mn],work[mn],dis[mn],q[mn];
void prepare(int _node,int _src,int _dest)
{
node=_node,src=_src,dest=_dest;
for(int i=0;i<node;i++) head[i]=-1;
edge=0;
}
void addedge(int u,int v,int c)
{
ver[edge]=v;flow[edge]=c;next[edge]=head[u];head[u]=edge++;
ver[edge]=u;flow[edge]=0;next[edge]=head[v];head[v]=edge++;
}
bool Dinic_bfs()
{
int i,u,v,l,r=0;
for(i=0;i<node;i++)
dis[i]=-1;
dis[q[r++]=src]=0;
for(l=0;l<r;l++)
for(i=head[u=q[l]];i>=0;i=next[i])
if(flow[i]&&dis[v=ver[i]]<0)
{
dis[q[r++]=v]=dis[u]+1;
if(v==dest) return 1;
}
return 0;
}
int Dinic_dfs(int u,int exp)
{
if(u==dest) return exp;
for(int &i=work[u],v,tmp;i>=0;i=next[i])
{
if(flow[i]&&dis[v=ver[i]]==dis[u]+1&&(tmp=Dinic_dfs(v,min(exp,flow[i])))>0)
{
flow[i]-=tmp;
flow[i^1]+=tmp;
return tmp;
}
}
return 0;
}
int Dinic_flow()
{
int i,ret=0,delta;
while(Dinic_bfs())
{
for(i=0;i<node;i++)
work[i]=head[i];
while(delta=Dinic_dfs(src,oo))  ret+=delta;
}
return ret;
}
int main()
{
int n,m,u,v,c;
while(~scanf("%d%d",&n,&m))
{
prepare(m+1,1,m);
while(n--)
{
scanf("%d%d%d",&u,&v,&c);
addedge(u,v,c);
}
printf("%d\n",Dinic_flow());
}
return 0;
}