AC自动机 板子

在Trie上做KMP

https://www.luogu.org/problemnew/show/3808

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#include<cstdio> #include<queue> #include<iostream> #define FOR(i,s,t) for(register int i=s;i<=t;++i) using std::cin; const int N=4000011; char s[N]; int tot,n,ans; namespace AC_automaton{     struct Tire{         int cnt,fail;         int to[27];     }tr[N];     inline void build_tire(){         int u=0;         for(register int i=0;s[i]!='\0';++i){             if(!tr[u].to[s[i]-'a'])                 tr[u].to[s[i]-'a']=++tot;             u=tr[u].to[s[i]-'a'];         }         ++tr[u].cnt;     }     inline void build_automaton(){              int v,u;         std::queue<int>q;         FOR(i,0,25)             if((v=tr[0].to[i]))                 q.push(v);         int now;         while(!q.empty()){             now=q.front();q.pop();             FOR(i,0,25){                 v=tr[now].to[i];                 u=tr[now].fail;                 if(v){                     tr[v].fail=tr[u].to[i];                     q.push(v);                 }                 else                     tr[now].to[i]=tr[u].to[i];             }         }     }     inline void match(){         int now=0,tmp;         for(register int i=0;s[i]!='\0';++i){             now=tr[now].to[s[i]-'a'];             tmp=now;             while(tmp&&tr[tmp].cnt!=-1){                 ans+=tr[tmp].cnt;                 tr[tmp].cnt=-1;                 tmp=tr[tmp].fail;             }         }     } } using namespace AC_automaton; int main(){     scanf("%d\n",&n);     while(n--){         scanf("%s",s);         build_tire();     }     tr[0].fail=0;     build_automaton();      scanf("%s",s);     match();     printf("%d\n",ans);     return 0; }

　　

https://www.luogu.org/problemnew/show/3796

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#include<cstdio> #include<queue> #define FOR(i,s,t) for(register int i=s;i<=t;++i) const int N=1000011; std::queue<int>q; namespace AC_automaton{     int ans[155];     char s[233][233];     char A[N];     struct Tire{         int fail;         int to[26];         int pos;         inline void init(){             fail=pos=0;             FOR(i,0,25)to[i]=0;         }     }tr[N];     int tot;     inline void insert(char *s,int pos){         int u=0,v;         for(register int i=0;s[i]!='\0';++i){             if(!tr[u].to[s[i]-'a'])                 tr[tr[u].to[s[i]-'a']=++tot].init();                    u=tr[u].to[s[i]-'a'];         }         tr[u].pos=pos;     }     inline void build_fail(){         int u,v,now;         FOR(i,0,25)             if((u=tr[0].to[i])){                 tr[u].fail=0;                 q.push(u);             }         while(!q.empty()){             now=q.front();q.pop();             FOR(i,0,25){                 v=tr[now].to[i];                 u=tr[now].fail;                 if(v){                     tr[v].fail=tr[u].to[i];                     q.push(v);                 }                 else                     tr[now].to[i]=tr[u].to[i];             }         }     }     inline void match(char *s){         int now=0,tmp;         for(register int i=0;s[i]!='\0';++i){             now=tr[now].to[s[i]-'a'];             tmp=now;             while(tmp){                 ++ans[tr[tmp].pos];                 tmp=tr[tmp].fail;             }         }     } } using namespace AC_automaton; int n,mx; int main(){     while(~scanf("%d",&n)&&n){         FOR(i,0,n)             ans[i]=0;         tot=0;         tr[0].fail=0;         tr[0].init();         FOR(i,1,n){             scanf("%s",s[i]);             insert(s[i],i);         }         build_fail();         scanf("%s",A);         match(A);         ans[0]=0;         mx=1;         FOR(i,1,n)             if(ans[mx]<ans[i])                 mx=i;         printf("%d\n",ans[mx]);         FOR(i,1,n)             if(ans[mx]==ans[i])                 printf("%s\n",s[i]);     }     return 0; }