bzoj1927

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 #define M0(a) memset(a, 0, sizeof(a))
 4 #define Inf 0x3fffffff
 5 const int maxn = 2010;
 6 const int maxm = 200010;
 7 struct edge{
 8      int v, f, c, next;
 9      edge(){}
10      edge(int _v, int _f, int _c, int _next):v(_v), f(_f), c(_c), next(_next){}
11 };
12 struct Costflow{
13      int last[maxn], pre[maxn], dis[maxn], vis[maxn];
14      int tot, S, T;
15      edge e[maxm];
16      void add(int u, int v, int f, int c){
17           e[tot] = edge(v, f, c, last[u]); last[u] = tot++;
18           e[tot] = edge(u, 0, -c, last[v]); last[v] = tot++; 
19      }
20      void init(int S, int T){
21           this->S = S, this->T = T;
22           M0(e);
23           memset(last, -1, sizeof(last));
24           tot = 0;     
25      }
26      int spfa(){
27           for (int i = 0; i <= T; ++i)
28               dis[i] = Inf;
29           memset(vis, 0, sizeof(vis));
30           memset(pre, -1, sizeof(pre));
31           dis[S] = 0;
32           queue<int> q;
33           q.push(S) , vis[S] = 1;
34           int p, u, v;
35           while (!q.empty()){
36                 p = last[u = q.front()];
37                 for ( ; p > -1; p = e[p].next){
38                        v = e[p].v;
39                        if (dis[u] + e[p].c < dis[v] && e[p].f > 0){
40                              dis[v] = dis[u] + e[p].c;
41                              pre[v] = p;
42                              if (!vis[v]) vis[v] = 1, q.push(v);
43                        }   
44                 }
45                 vis[u] = 0;
46                 q.pop();    
47           }
48           return dis[T] < Inf;  
49      }
50      int costflow(){
51           int cost = 0, flow = 0;
52           while (spfa()){
53                int f = Inf;
54                for (int p = pre[T]; p != -1; p = pre[e[p^1].v])
55                       f = min(f, e[p].f);
56                flow += f;
57                cost += f * dis[T];
58                for (int p = pre[T]; p != -1; p = pre[e[p^1].v])
59                       e[p].f -= f, e[p^1].f += f;     
60           }
61           return cost;
62      }
63      /***********/ 
64 } F;
65 int n, m;
66 int t[maxn];
67 
68 void solve(){
69 //     printf("%d %d\n", n, m);
70      for (int i = 1; i <= n; ++i)
71          scanf("%d", t+i);
72      int S = 0, T = 2 * n + 1;
73      F.init(S, T);
74      for (int i = 1; i <= n; ++i)
75          F.add(S, i + n, 1, t[i]), F.add(i+n, T, 1, 0), F.add(S, i, 1, 0);
76      int u, v, w;
77      for (int i = 1; i <= m; ++i){
78          scanf("%d%d%d", &u, &v, &w);
79          if (u > v) swap(u, v);
80          F.add(u, v+n, 1, w);
81      }
82      int ans = F.costflow();
83      cout << ans << endl;
84 }
85 
86 int main(){
87     while (scanf("%d%d", &n, &m) != EOF){
88         solve();
89     }            
90 }