bzoj1497: [NOI2006]最大获利

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
#define rep(i,n) for(int i=1;i<=n;i++)
#define clr(x,c) memset(x,c,sizeof(x))
int read(){
	int x=0;char c=getchar();bool f=true;
	while(!isdigit(c)){
		if(c==‘-‘) f=false;c=getchar();
	}
	while(isdigit(c)) x=x*10+c-‘0‘,c=getchar();
	return f?x:-x;
}
const int inf=0x7f7f7f7f;
const int nmax=60005;
const int maxn=200005;
struct edge{
	int to,cap;edge *next,*rev;
};
edge edges[maxn<<2],*pt,*head[nmax],*p[nmax],*cur[nmax];
void add(int u,int v,int d){
	pt->to=v;pt->cap=d;pt->next=head[u];head[u]=pt++;
}
void adde(int u,int v,int d){
	add(u,v,d);add(v,u,0);head[u]->rev=head[v];head[v]->rev=head[u];
}
int cnt[nmax],h[nmax];
int maxflow(int s,int t,int n){
	clr(cnt,0);clr(h,0);cnt[0]=n;
	int flow=0,a=inf,x=s;edge *e;
	while(h[s]<n){
		for(e=cur[x];e;e=e->next) if(e->cap>0&&h[e->to]+1==h[x]) break;
		if(e){
			p[e->to]=cur[x]=e;a=min(a,e->cap);x=e->to;
			if(x==t){
				while(x!=s) p[x]->rev->cap+=a,p[x]->cap-=a,x=p[x]->rev->to;
				flow+=a,a=inf;
			}
		}else{
			if(!--cnt[h[x]]) break;
			h[x]=n;
			for(e=head[x];e;e=e->next) if(e->cap>0&&h[e->to]+1<h[x]) h[x]=h[e->to]+1,cur[x]=e;
			cnt[h[x]]++;
			if(x!=s) x=p[x]->rev->to;
		}
	}
	return flow;
}
int main(){
	int n=read(),m=read(),tmp,ans=0,s=0,t=n+m+1;
	pt=edges;clr(head,0)
;	rep(i,n) adde(s,i,read());
	rep(i,m){
		adde(read(),i+n,inf);adde(read(),i+n,inf);adde(i+n,t,tmp=read());ans+=tmp;
	}
	printf("%d\n",ans-maxflow(s,t,n+m+2));
	return 0;
}