bzoj 1407

裸最大权封闭子图

#include<bits/stdc++.h>
#define inc(i,l,r) for(int i=l;i<=r;i++)
#define dec(i,l,r) for(int i=l;i>=r;i--)
#define link(x) for(edge *j=h[x];j;j=j->next)
#define mem(a) memset(a,0,sizeof(a))
#define inf 1e9
#define ll long long
#define succ(x) (1<<x)
#define NM 60000
#define nm 400000
using namespace std;
int read(){
    int x=0,f=1;char ch=getchar();
    while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
    while(isdigit(ch))x=x*10+ch-'0',ch=getchar();
    return x*f;
}
struct edge{
    int t,v;
    edge *next,*rev;
}e[nm],*h[NM],*o=e,*p[NM],*tmp[NM];
void _add(int x,int y,int v){
    o++;o->t=y;o->v=v;o->next=h[x];h[x]=o;
}
void add(int x,int y,int v){
    _add(x,y,v);_add(y,x,0);
    h[x]->rev=h[y];h[y]->rev=h[x];
}
int n,m,_x,_y,_t,_s,d[NM],cnt[NM];
int maxflow(){
    int flow=0;edge *j;
    inc(i,0,n)tmp[i]=h[i];
    cnt[0]=n+1;
    for(int x=0,s=inf;d[x]<n+1;){
        for(j=tmp[x];j;j=j->next)
        if(j->v&&d[x]==d[j->t]+1)break;
        if(j){
            s=min(s,j->v);tmp[x]=p[j->t]=j;
            if((x=j->t)==n){
                for(;x;x=p[x]->rev->t)
                p[x]->v-=s,p[x]->rev->v+=s;
                flow+=s;s=inf;
            }
        }else{
            if(!--cnt[d[x]])break;
            d[x]=n+1;
            link(x)
            if(j->v&&d[x]>d[j->t]+1){
                d[x]=d[j->t]+1;
                tmp[x]=j;
            }
            cnt[d[x]]++;
            if(x)x=p[x]->rev->t;
        }
    }
    return flow;
}
int main(){
    freopen("data.in","r",stdin);
    n=read();m=read();
    inc(i,1,n)add(0,i,read());
    inc(i,1,m){
        _x=read();_y=read();_t=read();_s+=_t;
        add(_x,i+n,inf);add(_y,i+n,inf);add(i+n,n+m+1,_t);
    }
    n=n+m+1;
    printf("%d
",_s-maxflow());
    return 0;
}