高效的网络流dinic算法模版

#include <cstring>

#include <algorithm>

#include <vector>

#define Maxn 120010

#define Maxm 210000

#define LL int

#define inf 100000000

#define Abs(a) (a)>0?(a):(-a)

using namespace std;

struct Edge{

    int from,to,next;

    LL val;

}edge[Maxm];

const double eps=1e-9;

LL value[Maxn];

int head[Maxn],work[Maxn],dis[Maxn],q[Maxn],e,vi[Maxn];

void init()

{

    e=0;

    memset(head,-1,sizeof(head));

}

void add1(int u,int v,LL c)//有向边

{

    edge[e].to=v;edge[e].val=c;edge[e].next=head[u];head[u]=e++;

    edge[e].to=u;edge[e].val=0;edge[e].next=head[v];head[v]=e++;

}

void add2(int u,int v,LL c)//无向边

{

    edge[e].to=v;edge[e].val=c;edge[e].next=head[u];head[u]=e++;

    edge[e].to=u;edge[e].val=c;edge[e].next=head[v];head[v]=e++;

}

int bfs(int S,int T)

{

    int rear=0;

    memset(dis,-1,sizeof(dis));

    dis[S]=0;q[rear++]=S;

    for(int i=0;i<rear;i++)

    {

        for(int j=head[q[i]];j!=-1;j=edge[j].next)

        {

            if(edge[j].val&&dis[edge[j].to]==-1)

            {

                dis[edge[j].to]=dis[q[i]]+1;

                q[rear++]=edge[j].to;

                if(edge[j].to==T) return 1;

            }

        }

    }

    return 0;

}

LL dfs(int cur,LL a,int T)

{

    if(cur==T) return a;

    for(int &i=work[cur];i!=-1;i=edge[i].next)

    {

        if(edge[i].val&&dis[edge[i].to]==dis[cur]+1)

        {

            LL t=dfs(edge[i].to,min(a,edge[i].val),T);

            if(t)

            {

                edge[i].val-=t;

                edge[i^1].val+=t;

                return t;

            }

        }

    }

    return 0;

}

LL Dinic(int S,int T)

{

    LL ans=0;

    while(bfs(S,T))

    {

        memcpy(work,head,sizeof(head));

        while(LL t=dfs(S,inf,T)) ans+=t;

    }

    return ans;

}

int main()

{

    int n,m,i,j,num=0;

    Dinic(0,n+1);

    for(i=1;i<=n;i++)//找出S的点的个数

        if(dis[i]>=0)

            num++;

    return 0;

}