bzoj1097: [POI2007]旅游景点atr

#include<cstdio>
#include<iostream>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<cmath>
#include<queue>
using namespace std;

struct node
{
    int x,y,d,next;
}a[410000];int len,last[21000];
void ins(int x,int y,int d)
{
    len++;
    a[len].x=x;a[len].y=y;a[len].d=d;
    a[len].next=last[x];last[x]=len;
}

int n,d[21000];bool v[21000];
struct dij
{
    int d,id;
    dij(){}
    dij(int D,int ID){d=D,id=ID;}
    friend bool operator>(dij d1,dij d2){return d1.d>d2.d;}
    friend bool operator<(dij d1,dij d2){return d1.d<d2.d;}
};priority_queue<dij,vector<dij>,greater<dij> >q;
int dijkstra(int st,int dis)
{
    memset(d,63,sizeof(d));d[st]=dis;
    memset(v,false,sizeof(v));
    q.push(dij(d[st],st));
    while(!q.empty())
    {
        dij tno=q.top();q.pop();
        if(v[tno.id]==true)continue;
        v[tno.id]=true;
        
        int x=tno.id;
        for(int k=last[x];k;k=a[k].next)
        {
            int y=a[k].y;
            if(d[y]>d[x]+a[k].d)
            {
                d[y]=d[x]+a[k].d;
                q.push(dij(d[y],y));
            }
        }
    }
    return d[n];
}

int K,mp[30][30],f[30][2100000],cq[30],th[30];
int DP()
{
    memset(f,63,sizeof(f));
    for(int i=2;i<=K;i++)
    {
        dijkstra(i,0);
        for(int j=2;j<=K;j++)
            mp[i][j]=min(mp[i][j],d[j]);
        th[i]=d[n];
        if(cq[i]==0)f[i][1<<i-2]=d[1];
    }
    int maxp=(1<<K-1)-1;
    for(int zt=0;zt<=maxp;zt++)
        for(int i=2;i<=K;i++)
            if(f[i][zt]!=f[0][0])
            {
                for(int j=2;j<=K;j++)
                {
                    int B=(1<<j-2);
                    if((zt&B)==0&&(zt&cq[j])==cq[j])
                        f[j][zt^B]=min(f[j][zt^B],f[i][zt]+mp[i][j]);
                }
            }
            
    int ret=(1<<30);
    for(int i=2;i<=K;i++)
        ret=min(ret,f[i][maxp]+th[i]);
    return ret;
}
int main()
{
    freopen("a.in","r",stdin);
    freopen("a.out","w",stdout);
    int m,x,y,dd;
    scanf("%d%d%d",&n,&m,&K);K++;
    len=0;memset(last,0,sizeof(last));
    memset(mp,63,sizeof(mp));
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d%d",&x,&y,&dd);
        ins(x,y,dd),ins(y,x,dd);
    }
    int U;
    scanf("%d",&U);
    memset(cq,0,sizeof(cq));
    while(U--)
    {
        scanf("%d%d",&x,&y);
        if(x!=1)cq[y]|=(1<<x-2);
    }
    
    if(K==1)
    {
        dijkstra(1,0);
        printf("%d\n",d[n]);
    }
    else printf("%d\n",DP());
    return 0;
}