noi2006day2_最大获利 网络流

这道题是上一题的数据加强版，dinic表示毫无压力；

 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include<string>
 #include<cstdlib>
 #include<ctime>
 #include<algorithm>
 using namespace std;
 const int maxn=;
 const int inf=;
 const int s=,t=;
 struct node{
     int y,next,flow,re;
 }e[maxn*];
 int linkk[maxn*],len=,n,m,w[maxn],sum=;
 void print(int x){printf("%d\n",x);}
 void print(int x,int y){printf("%d %d\n",x,y);}
 void insert(int x,int y,int flow){
     e[++len].y=y;e[len].flow=flow;
     e[len].next=linkk[x];linkk[x]=len;e[len].re=len+;
     e[++len].y=x;e[len].flow=;
     e[len].next=linkk[y];linkk[y]=len;e[len].re=len-;
 }
 void init(){
     scanf("%d%d",&n,&m);
     for(int i=;i<=n;i++)scanf("%d",&w[i]);
     int x,y,v;
     for(int i=;i<=m;i++){
         scanf("%d%d%d",&x,&y,&v);sum+=v;
         insert(s,i,v);insert(i,m+x,inf);insert(i,m+y,inf);
     }
     for(int i=;i<=n;i++)insert(m+i,t,w[i]);
 }
 int q[maxn],tail=,level[maxn],head=;
 bool bfs(){
     memset(level,-,sizeof(level));
     head=;tail=;level[s]=;q[++tail]=s;
     while(++head<=tail){
         int x=q[head];
         for(int i=linkk[x];i;i=e[i].next){
             if(level[e[i].y]==-&&e[i].flow){
                 q[++tail]=e[i].y;
                 level[e[i].y]=level[x]+;
             }
         }
     }
     return level[t]>;
 }
 int find(int x,int flow){
     if(x==t)return flow;
     int maxflow=,d=;
     for(int i=linkk[x];i&&maxflow<flow;i=e[i].next){
         if(level[e[i].y]==level[x]+&&e[i].flow){
             if(d=find(e[i].y,min(flow-maxflow,e[i].flow))){
                 maxflow+=d;
                 e[i].flow-=d;
                 e[e[i].re].flow+=d;
             }
         }
     }
     if(!maxflow)level[x]=-;
     return maxflow;
 }
 void work(){
     int d=,ans=;
     while(bfs())
         while(d=find(s,inf))
             ans+=d;
     cout<<sum-ans<<endl;
 }
 int main(){
     freopen("1.in","r",stdin);
     freopen("1.out","w",stdout);
     init();
     work();
 }