BZOJ 3511 土地划分

随便建个最小割啦。。。

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
#define maxv 50050
#define maxe 500050
#define inf 0x7f7f7f7f7f7f7f7fLL
using namespace std;
long long n,m,vala[maxv],valb[maxv],sum=0,max_flow=0,x,y,a,b,c,s=1,t,nume=1,g[maxv];
long long dis[maxv];
struct edge
{
    long long v,f,nxt;
}e[maxe];
queue <long long> q;
void addedge(long long u,long long v,long long f)
{
    e[++nume].v=v;e[nume].f=f;
    e[nume].nxt=g[u];g[u]=nume;
    e[++nume].v=u;e[nume].f=0;
    e[nume].nxt=g[v];g[v]=nume;
}
bool bfs()
{
    for (long long i=s;i<=t;i++) dis[i]=inf;
    dis[s]=0;q.push(s);
    while (!q.empty())
    {
        long long head=q.front();q.pop();
        for (long long i=g[head];i;i=e[i].nxt)
        {
            long long v=e[i].v;
            if ((e[i].f>0) && (dis[v]>dis[head]+1))
            {
                dis[v]=dis[head]+1;
                q.push(v);
            }
        }
    }
    return dis[t]!=inf;
}
long long dinic(long long x,long long low)
{
    if (x==t) return low;
    long long ret=0;
    for (long long i=g[x];low && i;i=e[i].nxt)
    {
        long long v=e[i].v;
        if ((e[i].f>0) && (dis[v]==dis[x]+1))
        {
            long long dd=dinic(v,min(low,e[i].f));
            ret+=dd;low-=dd;
            e[i].f-=dd;e[i^1].f+=dd;
        }
    }
    if (!ret) dis[x]=inf;
    return ret;
}
int main()
{
    scanf("%lld%lld",&n,&m);t=n;
    for (long long i=2;i<=n-1;i++) {scanf("%lld",&vala[i]);sum+=vala[i];vala[i]<<=1;}
    for (long long i=2;i<=n-1;i++) {scanf("%lld",&valb[i]);sum+=valb[i];valb[i]<<=1;}
    for (long long i=1;i<=m;i++)
    {
        scanf("%lld%lld%lld%lld%lld",&x,&y,&a,&b,&c);sum+=a+b;
        if (x>y) swap(x,y);
        if ((x==1) && (y==n))
        {
            sum-=a+b+c;
            continue;
        }
        if (x==1) vala[y]+=2*a+2*c,sum-=b;
        else if (y==n) valb[x]+=2*b+2*c,sum-=a;
        else vala[x]+=a,valb[x]+=b,vala[y]+=a,valb[y]+=b;
        if ((x!=1) && (y!=n)) addedge(x,y,a+b+2*c),addedge(y,x,a+b+2*c);
    }
    for (long long i=2;i<=n-1;i++) addedge(s,i,vala[i]),addedge(i,t,valb[i]);
    while (bfs())
        max_flow+=dinic(s,inf);
    printf("%lld\n",sum-max_flow/2);
    return 0;
}