HDU 3488 Tour

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 const int maxn = 310;
 4 const int INF = 0x3f3f3f3f;
 5 int W[maxn][maxn],Lx[maxn],Ly[maxn],slack[maxn];
 6 int n,Link[maxn];
 7 bool S[maxn],T[maxn];
 8 bool match(int u) {
 9     S[u] = true;
10     for(int v = 1; v <= n; ++v) {
11         if(T[v]) continue;
12         int d = Lx[u] + Ly[v] - W[u][v];
13         if(!d) {
14             T[v] = true;
15             if(Link[v] == -1 || match(Link[v])) {
16                 Link[v] = u;
17                 return true;
18             }
19         }else if(slack[v] > d) slack[v] = d;
20     }
21     return false;
22 }
23 void update() {
24     int d = INF;
25     for(int v = 1; v <= n; ++v)
26         if(!T[v] && slack[v] < d)
27             d = slack[v];
28     for(int u = 1; u <= n; ++u) {
29         if(S[u]) Lx[u] -= d;
30         if(T[u]) Ly[u] += d;
31         else slack[u] -= d;
32     }
33 }
34 int KuhnMunkras() {
35     for(int u = 1; u <= n; ++u) {
36         Lx[u] = -INF;
37         Ly[u] = 0;
38         Link[u] = -1;
39         for(int v = 1; v <= n; ++v)
40             Lx[u] = max(Lx[u],W[u][v]);
41     }
42     for(int u = 1; u <= n; ++u) {
43         for(int v = 1; v <= n; ++v)
44             slack[v] = INF;
45         while(true) {
46             memset(S,false,sizeof S);
47             memset(T,false,sizeof T);
48             if(match(u)) break;
49             update();
50         }
51     }
52     int ret = 0;
53     for(int v = 1; v <= n; ++v)
54         if(Link[v] > -1) ret += W[Link[v]][v];
55     return ret;
56 }
57 
58 int main() {
59     int m,u,v,w,kase;
60     scanf("%d",&kase);
61     while(kase--) {
62         scanf("%d%d",&n,&m);
63         for(int i = 1; i <= n; ++i)
64             for(int j = 1; j <= n; ++j)
65                 W[i][j] = -INF;
66         for(int i = 0; i < m; ++i){
67             scanf("%d%d%d",&u,&v,&w);
68             W[u][v] = max(W[u][v],-w);
69         }
70         printf("%d\n",-KuhnMunkras());
71     }
72     return 0;
73 }