[NOIp2017提高组]宝藏

#include<cstdio>
#include<cctype>
#include<algorithm>
inline int getint() {
    register char ch;
    while(!isdigit(ch=getchar()));
    register int x=ch^'0';
    while(isdigit(ch=getchar())) x=(((x<<2)+x)<<1)+(ch^'0');
    return x;
}
const int inf=0x7fffffff;
const int N=12;
int n,w[N][N],dep[N],f[1<<N];
void dfs(const int state) {
    for(register int i=0;i<n;i++) {
        if(!(state&(1<<i))) continue;
        for(register int j=0;j<n;j++) {
            if(state&(1<<j)) continue;
            if(w[i][j]==inf) continue;
            if(f[state]+w[i][j]*(dep[i]+1)<f[state|(1<<j)]) {
                const int tmp=dep[j];
                dep[j]=dep[i]+1;
                f[state|(1<<j)]=f[state]+w[i][j]*(dep[i]+1);
                dfs(state|(1<<j));
                dep[j]=tmp;
            }
        }
    }
}
int main() {
    n=getint();
    for(register int i=0;i<n;i++) {
        for(register int j=0;j<n;j++) {
            w[i][j]=inf;
        }
    }
    for(register int m=getint();m;m--) {
        const int u=getint()-1,v=getint()-1;
        w[u][v]=w[v][u]=std::min(w[u][v],getint());
    }
    int ans=inf;
    for(register int i=0;i<n;i++) {
        for(register int i=0;i<n;i++) dep[i]=inf;
        for(register int i=1;i<(1<<n);i++) f[i]=inf;
        dep[i]=f[1<<i]=0;
        dfs(1<<i);
        ans=std::min(ans,f[(1<<n)-1]);
    }
    printf("%d\n",ans);
    return 0;
}