SDTSC 2010 starrace
题意：给你一个图 让你求经过所有点的一条最短路径 终点无所谓
做法：
有人竟然费用流屎过。。
我的做法是上下界费用流
A->A' 下界是1 然后就建图了
1
#include
<
cstdio
>
2 #include < cstring >
3 #define min(a,b) ((a)<(b)?(a):(b))
4 #define n 2047
5 #define e 300005
6 int vtx[e],w[e],f[e],ne[e],tot = 1 ;
7 int L[n],q[n + 1 ],pre[n],d[n],N,M,hidden,S,T,SuperS,SuperT,Cost;
8 bool vis[n];
9 inline void Ins( int u, int v, int fl, int cost)
10 {
11 vtx[ ++ tot] = v;f[tot] = fl;w[tot] = cost;ne[tot] = L[u];L[u] = tot;
12 vtx[ ++ tot] = u;f[tot] = 0 ;w[tot] =- cost;ne[tot] = L[v];L[v] = tot;
13 }
14 inline bool spfa()
15 {
16 memset(vis, 0 , sizeof (vis));
17 memset(d, 63 , sizeof (d));
18 d[q[ 1 ] = SuperS] = 0 ,vis[SuperS] = 1 ;
19 for ( int h = 0 ,t = 1 ,u;h != t;vis[u] = 0 )
20 {
21 u = q[h = (h + 1 ) & n];
22 for ( int p = L[u],v = vtx[p];p;v = vtx[p = ne[p]])
23 if (f[p] && d[u] + w[p] < d[v])
24 {
25 d[v] = d[u] + w[p],pre[v] = p;
26 if ( ! vis[v]) vis[q[t = (t + 1 ) & n] = v] = 1 ;
27 }
28 }
29 return d[SuperT] < 1 << 29 ;
30 }
31 inline void push()
32 {
33 int fl = 1 << 30 ;
34 for ( int i = SuperT;i != SuperS;i = vtx[pre[i] ^ 1 ])
35 fl = min(fl,f[pre[i]]);
36 Cost += d[SuperT] * fl;
37 for ( int i = SuperT;i != SuperS;i = vtx[pre[i] ^ 1 ])
38 f[pre[i]] -= fl,f[pre[i] ^ 1 ] += fl;
39 }
40 int main()
41 {
42 int u,v,w;
43 freopen( " starrace.in " , " r " ,stdin);
44 freopen( " starrace.out " , " w " ,stdout);
45 scanf( " %d%d " , & N, & M);
46 hidden = 2 * N + 1 ;
47 S = hidden + 1 ,T = S + 1 ,SuperS = T + 1 ,SuperT = SuperS + 1 ;
48 Ins(S,hidden, 1 , 0 );
49 for ( int i = 1 ;i <= N; ++ i)
50 {
51 scanf( " %d " , & w);
52 Ins(hidden,i, 1 ,w);
53 Ins(i + N,hidden, 1 , 0 );
54 Ins(i + N,T, 1 , 0 );
55 Ins(SuperS,i + N, 1 , 0 );
56 Ins(i,SuperT, 1 , 0 );
57 }
58 Ins(T,S, 1 << 30 , 0 );
59 for ( int i = 1 ;i <= M; ++ i)
60 {
61 scanf( " %d%d%d " , & u, & v, & w);
62 if (u > v) { int t = u;u = v;v = t;}
63 Ins(u + N,v, 1 ,w);
64 }
65 for (;spfa();push());
66 printf( " %d\n " ,Cost);
67 return 0 ;
68 }
69
2 #include < cstring >
3 #define min(a,b) ((a)<(b)?(a):(b))
4 #define n 2047
5 #define e 300005
6 int vtx[e],w[e],f[e],ne[e],tot = 1 ;
7 int L[n],q[n + 1 ],pre[n],d[n],N,M,hidden,S,T,SuperS,SuperT,Cost;
8 bool vis[n];
9 inline void Ins( int u, int v, int fl, int cost)
10 {
11 vtx[ ++ tot] = v;f[tot] = fl;w[tot] = cost;ne[tot] = L[u];L[u] = tot;
12 vtx[ ++ tot] = u;f[tot] = 0 ;w[tot] =- cost;ne[tot] = L[v];L[v] = tot;
13 }
14 inline bool spfa()
15 {
16 memset(vis, 0 , sizeof (vis));
17 memset(d, 63 , sizeof (d));
18 d[q[ 1 ] = SuperS] = 0 ,vis[SuperS] = 1 ;
19 for ( int h = 0 ,t = 1 ,u;h != t;vis[u] = 0 )
20 {
21 u = q[h = (h + 1 ) & n];
22 for ( int p = L[u],v = vtx[p];p;v = vtx[p = ne[p]])
23 if (f[p] && d[u] + w[p] < d[v])
24 {
25 d[v] = d[u] + w[p],pre[v] = p;
26 if ( ! vis[v]) vis[q[t = (t + 1 ) & n] = v] = 1 ;
27 }
28 }
29 return d[SuperT] < 1 << 29 ;
30 }
31 inline void push()
32 {
33 int fl = 1 << 30 ;
34 for ( int i = SuperT;i != SuperS;i = vtx[pre[i] ^ 1 ])
35 fl = min(fl,f[pre[i]]);
36 Cost += d[SuperT] * fl;
37 for ( int i = SuperT;i != SuperS;i = vtx[pre[i] ^ 1 ])
38 f[pre[i]] -= fl,f[pre[i] ^ 1 ] += fl;
39 }
40 int main()
41 {
42 int u,v,w;
43 freopen( " starrace.in " , " r " ,stdin);
44 freopen( " starrace.out " , " w " ,stdout);
45 scanf( " %d%d " , & N, & M);
46 hidden = 2 * N + 1 ;
47 S = hidden + 1 ,T = S + 1 ,SuperS = T + 1 ,SuperT = SuperS + 1 ;
48 Ins(S,hidden, 1 , 0 );
49 for ( int i = 1 ;i <= N; ++ i)
50 {
51 scanf( " %d " , & w);
52 Ins(hidden,i, 1 ,w);
53 Ins(i + N,hidden, 1 , 0 );
54 Ins(i + N,T, 1 , 0 );
55 Ins(SuperS,i + N, 1 , 0 );
56 Ins(i,SuperT, 1 , 0 );
57 }
58 Ins(T,S, 1 << 30 , 0 );
59 for ( int i = 1 ;i <= M; ++ i)
60 {
61 scanf( " %d%d%d " , & u, & v, & w);
62 if (u > v) { int t = u;u = v;v = t;}
63 Ins(u + N,v, 1 ,w);
64 }
65 for (;spfa();push());
66 printf( " %d\n " ,Cost);
67 return 0 ;
68 }
69