HDU4511 AC自动机+dijkstra

  1 #include <bits/stdc++.h>
  2 #include <cstdio>
  3 #include <iostream>
  4 #include <algorithm>
  5 #define ll long long
  6 #define lson l, m, rt<<1
  7 #define rson m+1, r, rt<<1|1
  8 #define st first
  9 #define nd second
 10 #define mp make_pair
 11 #define pii pair<int, int>
 12 #define pdi pair<double, int>
 13 #define gg puts("gg");
 14 //#define local
 15 //#define out1
 16 using namespace std;
 17 const int N  = 6e4+10;
 18 const int inf = 0x3f3f3f3f;
 19 int id(int c){
 20     return c-1;
 21 }
 22 struct Tire{
 23     int nex[N][50], fail[N],end[N], ch[N];
 24     int root, L, tot;
 25     int newnode(){
 26         memset(nex[L], -1, sizeof(nex[L]));
 27         end[L] = 0;
 28         ch[L] = 0;
 29         return L++;
 30     }
 31     void init(){
 32         L = tot = 0;
 33         root = newnode();
 34     }
 35     void insert(int* s, int len, int tag){
 36         int now = root;
 37         for(int i = 0; i < len; i++){
 38             int p = id(s[i]);
 39             if(nex[now][p] == -1)
 40                 nex[now][p] = newnode();
 41             now = nex[now][p];
 42             ch[now] = p;
 43         }
 44         end[now] = tag;
 45     }
 46     void build(){
 47         queue<int> Q;
 48         fail[root] = root;
 49         for(int i = 0; i < 50; i++){
 50             int& u = nex[root][i];
 51             if(u == -1)
 52                 u = root;
 53             else{
 54                 fail[u] = root;
 55                 Q.push(u);
 56             }
 57         }
 58         while(!Q.empty()){
 59             int now = Q.front();
 60             Q.pop();
 61             for(int i = 0; i < 50; i++){
 62                 int& u = nex[now][i];
 63                 if(u == -1)
 64                     u = nex[ fail[now] ][i];
 65                 else{
 66                     fail[u] = nex[ fail[now] ][i];
 67                     end[u] |= end[ fail[u] ];
 68                     Q.push(u);
 69                 }
 70             }
 71         }
 72     }
 73 };
 74 Tire ac;
 75 ll x[55], y[55];
 76 double w[55][55];
 77 int s[10];
 78 vector< pdi > ve[505];
 79 priority_queue< pdi, vector< pdi >, greater< pdi > >Q;
 80 double d[505];
 81 double dijkstra(int S){
 82     int i, x;
 83     for(i = 0; i < 505; i++) d[i] = 1e30;
 84     Q.push(mp(d[S]=0,S));
 85     while(!Q.empty()){
 86         pdi t = Q.top(); Q.pop();
 87         if(d[x = t.nd] < t.st) continue;
 88         for(i = 0; i < ve[x].size(); i++)
 89             if(d[x]+ve[x][i].st < d[ve[x][i].nd]){
 90                 d[ve[x][i].nd] = d[x]+ve[x][i].st;
 91                 Q.push( mp(d[ve[x][i].nd], ve[x][i].nd) );
 92             }
 93     }
 94 }
 95 int main(){
 96     int n, m, ca = 1;
 97     while(~scanf("%d%d", &n, &m), n+m){
 98         for(int i = 1; i <= n; i++)
 99             scanf("%lld%lld", x+i, y+i);
100         for(int i = 0; i <= n; i++)
101             for(int j = 0; j <= n; j++) w[i][j] = 1e30;
102         for(int i = 1; i <= n; i++)
103             for(int j = i+1; j <= n; j++)
104                 w[i][j] = sqrt( 1.0*(x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j]) );
105 
106         ac.init();
107         for(int i = 1; i <= n; i++){
108             s[0] = i;
109             ac.insert(s, 1, 0);
110         }
111 
112         for(int i = 1; i <= m; i++){
113             int k; scanf("%d", &k);
114             for(int j = 0; j < k; j++)
115                 scanf("%d", s+j);
116             ac.insert(s, k, 1);
117         }
118         ac.build();
119         for(int i = 0; i < ac.L; i++) ve[i].clear();
120         for(int i = 1; i < ac.L; i++){
121             int u = ac.ch[i]+1;
122             for(int j = u+1; j <= n; j++) {
123                 int to = ac.nex[i][id(j)];
124                 if(!ac.end[to]) ve[i].push_back( mp(w[u][j], to) );
125             }
126         }
127 
128         dijkstra(ac.nex[0][id(1)]);
129         double ans = 1e30;
130         for(int i = 1; i < ac.L; i++){
131             if(ac.ch[i] == id(n))
132                 ans = min(ans, d[i]);
133         }
134         if(ans < 1e25)
135             printf("%.2f\n", ans);
136         else
137             puts("Can not be reached!");
138     }
139     return 0;
140 }