hdu4511小明系列故事——女友的考验(ac自动机+最短路）

链接

预处理出来任意两点的距离，然后可以顺着trie树中的节点走，不能走到不合法的地方，另开一维表示走到了哪里，依次来更新。

注意判断一下起点是不是合法。

 #include <iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #include<stdlib.h>
 #include<vector>
 #include<cmath>
 #include<queue>
 #include<set>
 using namespace std;
 #define N 510
 #define LL long long
 const double eps = 1e-;
 const double pi = acos(-1.0);
 const double INF = 1e21;
 const int child_num = ;
 double w[][];
 class AC
 {
     private:
     int ch[N][child_num];
     int fail[N];
     int val[N];
     int id[];
     int Q[N];
     double dis[][N];
     int sz;
     public:
     void init()
     {
         fail[] = ;
         for(int i =  ; i< child_num ; i++)
         id[i] = i;
     }
     void reset()
     {
         memset(ch[],,sizeof(ch[]));
         memset(val,,sizeof(val));
         sz = ;
     }
     void insert(int *a,int k,int key)
     {
         int i,p=;
         for(i = ;i <= k; i++)
         {
             int d = a[i];
             if(ch[p][d]==)
             {
                 memset(ch[sz],,sizeof(ch[sz]));
                 ch[p][d]= sz++;
             }
             p = ch[p][d];
         }
         val[p] = key;
     }
     void construct()
     {
         int i,head=  ,tail = ;
         for(i =  ;i < child_num ; i++)
         {
             if(ch[][i])
             {
                 fail[ch[][i]] = ;
                 Q[tail++] = ch[][i];
             }
         }
         while(head!=tail)
         {
             int u = Q[head++];
             val[u]|=val[fail[u]];
             for(i = ; i < child_num ; i++)
             {
                 if(ch[u][i])
                 {
                     fail[ch[u][i]] = ch[fail[u]][i];
                     Q[tail++] = ch[u][i];
                 }
                 else ch[u][i] = ch[fail[u]][i];
             }
         }
     }
     void work(int n)
     {
         int i,j,g;
         for(i = ; i <= n ;i++)
         for(j =  ; j <= sz ;j++)
         dis[i][j] = INF;
         if(val[])
         {
             puts("Can not be reached!");
             return ;
         }
         dis[][ch[][]] = ;
         for(i =  ; i <= n ;i++)
         {
             for(j = ; j < sz ;j++)
             {
                 for(g = ; g <= n ;g++)
                 {
                     int np = ch[j][g];
                     if(val[np]) continue;
                     dis[g][np] = min(dis[g][np],dis[i][j]+w[i][g]);
                 }
             }
         }
         double ans = INF;
         for(i =  ; i < sz ; i++)
         {
             ans = min(ans,dis[n][i]);
         }
         if(fabs(ans-INF)<eps) puts("Can not be reached!");
         else
         printf("%.2f\n",ans);
     }
 }ac;
 struct node
 {
     double x,y;
 }pp[];
 double cdis(node a,node b)
 {
     return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));
 }
 int a[];
 int main()
 {
     int n,m,k,i,j;
     ac.init();
     while(scanf("%d%d",&n,&m)&&n&&m)
     {
         ac.reset();
         for(i =  ;i <= n; i++)
         {
             scanf("%lf%lf",&pp[i].x,&pp[i].y);
         }
         for(i = ; i <= n ;i++)
             for(j = ; j <= n ;j++)
             w[i][j] = cdis(pp[i],pp[j]);
         for(i = ; i <= m ; i++)
         {
             scanf("%d",&k);
             for(j=  ;j <= k; j++)
             scanf("%d",&a[j]);
             ac.insert(a,k,);
         }
         ac.construct();
         ac.work(n);
     }
     return ;
 }