hdu4057Rescue the Rabbit(ac自动机+dp)

链接

当时是因为没有做出来这道题才开了自动机的专题，现在看看还是比较简单的。

因为每个病毒串只算一次，只有10个病毒串，可以状压一下哪些状态是可以达到的，最后取一个最大值。

 #include <iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #include<stdlib.h>
 #include<vector>
 #include<cmath>
 #include<queue>
 #include<set>
 #include<string>
 using namespace std;
 #define N 1005
 #define LL long long
 #define INF 0xfffffff
 const double eps = 1e-;
 const double pi = acos(-1.0);
 const double inf = ~0u>>;
 const int child_num = ;
 char vir[];
 int v[];
 class AC
 {
     private:
     int ch[N][child_num];
     int fail[N];
     int Q[N];
     int val[N];
     int sz;
     int id[];
     int dp[][N][<<];
     char s[N];
     public:
     void init()
     {
         fail[] = ;
         id['A'] = ,id['G'] = ,id['T'] = ,id['C'] = ;
     }
     void reset()
     {
         memset(ch[],,sizeof(ch[]));
         memset(val,,sizeof(val));
         sz = ;
     }
     void insert(char *a,int key)
     {
         int p = ;
         for(; *a ; a++)
         {
             int d= id[*a];
             if(ch[p][d]==)
             {
                 memset(ch[sz],,sizeof(ch[sz]));
                 s[sz] = *a;
                 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 m)
     {
         int i,j,g;
         memset(dp,,sizeof(dp));
         dp[][][] = ;
         for(i =  ;i < n ;i++)
         {
             memset(dp[(i+)%],,sizeof(dp[(i+)%]));
             for(j =  ;j < sz ; j++)
             {
                 for(int e =  ; e < (<<m) ; e++)
                 {
                     if(!dp[i%][j][e]) continue;
                     for(g =  ; g < child_num ; g++)
                     {
                         int o = val[ch[j][g]];
                         dp[(i+)%][ch[j][g]][e|o] = dp[i%][j][e];
                     }
                 }
             }
         }
         int cnt = -INF;
         for(i =  ;i < sz ; i++)
         {
             for(j =  ;j < (<<m) ; j++)
             {
                 int ans = ;
                 if(!dp[n%][i][j]) continue;
                 for(g =  ; g < m ;g++)
                 {
                     if(j&(<<g))
                     ans+=v[g];
                 }
                 cnt = max(ans,cnt);
             }
         }
         if(cnt<)
         puts("No Rabbit after 2012!");
         else
         printf("%d\n",cnt);
     }
 }ac;
 int main()
 {
     int n,i,m;
     ac.init();
     while(scanf("%d%d",&m,&n)!=EOF)
     {
         ac.reset();
         for(i = ;i <= m ;i++)
         {
             scanf("%s%d",vir,&v[i-]);
             ac.insert(vir,i-);
         }
         ac.construct();
         ac.work(n,m);
     }
     return ;
 }