huijiagai

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<algorithm>
 4 #define inf 1000000000
 5 using namespace std;
 6 int ans=inf,n,m,num[5000],dp[5000][15],dis[15][15],dvs[5000][5000],ff[5000][15];
 7 int mmin(int a,int b){
 8     if(a==-1)return b;
 9     if(b==-1)return a;
10     return min(a,b);
11 }
12 int main()
13 {
14     scanf("%d%d",&n,&m);
15     int mass=(1<<n)-1;
16     for(int i=1;i<=n;i++)num[1<<(i-1)]=i;
17     for(int i=1;i<=n;i++)for(int j=1;j<=n;j++)dis[i][j]=inf;
18     for(int i=1;i<=n;i++)dis[i][i]=0; 
19     for(int i=1;i<=m;i++){
20         int u,v,w;scanf("%d%d%d",&u,&v,&w);
21         dis[u][v]=min(dis[u][v],w);
22         dis[v][u]=dis[u][v];
23     }
24     if(n==1){
25         printf("0\n");return 0;
26     }
27     for(int k=1;k<=n;k++)
28      for(int i=1;i<=n;i++)
29       for(int j=1;j<=n;j++)dis[i][j]=min(dis[i][j],dis[i][k]+dis[k][j]);
30     for(int s1=1;s1<=mass;s1++){
31         for(int i=1;i<=n;i++){
32             ff[s1][i]=inf;
33             for(int j=1;j<=n;j++)if((s1&(1<<(j-1)))>0)ff[s1][i]=min(ff[s1][i],dis[i][j]);
34         }
35     }
36     for(int s1=0;s1<=mass;s1++)
37     {
38         dvs[s1][0]=0;
39         for(int s2=1;s2<=mass;s2++)dvs[s1][s2]=inf;
40     } 
41     for(int s1=1;s1<=mass;s1++){
42         for(int s2=1;s2<=mass;s2++)if((s1&s2)==0){
43             int j=num[s2&(-s2)];
44             dvs[s1][s2]=dvs[s1][s2-(s2&(-s2))]+ff[s1][j];
45             //printf("%d %d %d %d\n",s1,s2,j,dvs[s1][s2]);
46         }
47     }
48         memset(dp,-1,sizeof(dp));
49         for(int i=1;i<=n;i++)dp[1<<(i-1)][0]=0;
50         for(int i=0;i<=n;i++)
51         for(int sta=1;sta<=mass;sta++){
52             int vs=sta^mass,v1=vs;
53             if(dp[sta][i]==-1)continue;
54             while(vs>0){
55                 if(dvs[sta][vs]<inf)
56                 dp[sta|vs][i+1]=mmin(dp[sta|vs][i+1],dp[sta][i]+dvs[sta][vs]*(i+1));
57                 //printf("==%d %d %d %d %d\n",sta,vs,sta|vs,i+1,dp[sta|vs][i+1]);
58                 vs=v1&(vs-1);
59             }    
60         }
61     for(int i=1;i<=n+1;i++)ans=mmin(ans,dp[mass][i]);
62     printf("%d\n",ans);
63     return 0;
64 }