裸最大权封闭子图

 1 #include<bits/stdc++.h>
 2 #define inc(i,l,r) for(int i=l;i<=r;i++)
 3 #define dec(i,l,r) for(int i=l;i>=r;i--)
 4 #define link(x) for(edge *j=h[x];j;j=j->next)
 5 #define mem(a) memset(a,0,sizeof(a))
 6 #define inf 1e9
 7 #define ll long long
 8 #define succ(x) (1<<x)
 9 #define NM 60000
10 #define nm 400000
11 using namespace std;
12 int read(){
13     int x=0,f=1;char ch=getchar();
14     while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
15     while(isdigit(ch))x=x*10+ch-'0',ch=getchar();
16     return x*f;
17 }
18 struct edge{
19     int t,v;
20     edge *next,*rev;
21 }e[nm],*h[NM],*o=e,*p[NM],*tmp[NM];
22 void _add(int x,int y,int v){
23     o++;o->t=y;o->v=v;o->next=h[x];h[x]=o;
24 }
25 void add(int x,int y,int v){
26     _add(x,y,v);_add(y,x,0);
27     h[x]->rev=h[y];h[y]->rev=h[x];
28 }
29 int n,m,_x,_y,_t,_s,d[NM],cnt[NM];
30 int maxflow(){
31     int flow=0;edge *j;
32     inc(i,0,n)tmp[i]=h[i];
33     cnt[0]=n+1;
34     for(int x=0,s=inf;d[x]<n+1;){
35         for(j=tmp[x];j;j=j->next)
36         if(j->v&&d[x]==d[j->t]+1)break;
37         if(j){
38             s=min(s,j->v);tmp[x]=p[j->t]=j;
39             if((x=j->t)==n){
40                 for(;x;x=p[x]->rev->t)
41                 p[x]->v-=s,p[x]->rev->v+=s;
42                 flow+=s;s=inf;
43             }
44         }else{
45             if(!--cnt[d[x]])break;
46             d[x]=n+1;
47             link(x)
48             if(j->v&&d[x]>d[j->t]+1){
49                 d[x]=d[j->t]+1;
50                 tmp[x]=j;
51             }
52             cnt[d[x]]++;
53             if(x)x=p[x]->rev->t;
54         }
55     }
56     return flow;
57 }
58 int main(){
59     freopen("data.in","r",stdin);
60     n=read();m=read();
61     inc(i,1,n)add(0,i,read());
62     inc(i,1,m){
63         _x=read();_y=read();_t=read();_s+=_t;
64         add(_x,i+n,inf);add(_y,i+n,inf);add(i+n,n+m+1,_t);
65     }
66     n=n+m+1;
67     printf("%d\n",_s-maxflow());
68     return 0;
69 }
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posted on 2016-01-30 15:46  onlyRP  阅读(129)  评论(0编辑  收藏  举报