POJ 2987 最大流最小割最大权闭合图

#include<iostream>
#include<cstdio>
#define INF 2100000000000560ll
#define MN 5555
#define MM 555555
#define CC(a) memset( a,0,sizeof(a) )
#define FF(i,N) for( int i=0;i<N;i++ )
template<class T>inline void checkmin( T&a,T b ){ if( a>b||a==-1 ) a=b; }
using namespace std;

typedef long long ll;
ll n,m,s,t,alloc,tot;
struct edge{
ll pos,next,c;
}E[MM];
ll cur[MN],gap[MN],dis[MN],pre[MN],head[MN];

void addEdge( ll u,ll v,ll c,ll cc=0 )
{
E[alloc].pos=v;
E[alloc].c=c;
E[alloc].next=head[u];
head[u]=alloc++;

E[alloc].pos=u;
E[alloc].c=cc;
E[alloc].next=head[v];
head[v]=alloc++;
}

void setG()
{
ll u,v,cap;
CC(E);
memset( head,-1,sizeof(head) );
s=0,t=n+1;alloc=0;tot=0;
for( int i=1;i<=n;i++ ){
scanf( "%lld",&cap );
if( cap>0 ){
addEdge( s,i,cap );
tot+=cap;
}
if( cap<0 )
addEdge( i,t,-cap );
}
FF(i,m){
scanf( "%d%d",&u,&v );
addEdge( u,v,INF );
}
}

ll sap()
{
CC(dis),CC(gap);
FF( i,t+1 ) cur[i]=head[i];
int u=pre[s]=s;
ll maxflow=0,aug=-1;
gap[0]=t+1;
while( dis[s]<=t ){
loop:
for( ll &i=cur[u];i!=-1;i=E[i].next )
{
ll v=E[i].pos;
if( E[i].c&&dis[u]==dis[v]+1 )
{
pre[v]=u;
checkmin( aug,E[i].c );
u=v;
if( v==t )
{
maxflow+=aug;
//printf( "%d\n",maxflow );
for( u=pre[u];v!=s;v=u,u=pre[u] )
E[cur[u]].c-=aug,E[cur[u]^1].c+=aug;
aug=-1;
}
goto loop;
}

}
ll mind=t;
for( ll i=head[u];i!=-1;i=E[i].next )
{
ll v=E[i].pos;
if( E[i].c&&mind>dis[v] )
cur[u]=i,mind=dis[v];
}
if( --gap[dis[u]]==0 ) break;
gap[dis[u]=mind+1]++;
u=pre[u];
}
return maxflow;
}

ll sum,vis[MN];
void dfs( ll cur )
{
if( cur==t ) return ;
sum++;
vis[cur]=true;
for( ll i=head[cur];i!=-1;i=E[i].next )
if( vis[E[i].pos]==false&&E[i].c )
dfs(E[i].pos);
}

int main()
{
while( scanf("%d%d",&n,&m)!=EOF )
{
setG();
ll ans=tot-sap();
sum=0;CC(vis);
dfs(s);
printf( "%lld %lld\n",sum-1,ans );
}
return 0;
}