POJ1509 Glass Beads 【后缀自动机】

题目分析：

模板练手。看最长能走多远。

代码:

 #include<iostream>
 #include<cstdio>
 #include<cstdlib>
 #include<cstring>
 #include<string>
 using namespace std;

 const int maxn = ;

 int son[maxn][],fa[maxn],maxlen[maxn],root,num;

 string str;

 int addnew(int dt){maxlen[++num] = dt;return num;}
 int ins(char x,int p){
     int np = addnew(maxlen[p]+);
     while(p && !son[p][x-'a']) son[p][x-'a'] = np,p = fa[p];
     if(!p){fa[np] = root; return np;}
     else{
     int q = son[p][x-'a'];
     if(maxlen[q]==maxlen[p]+){fa[np]=q;return np;}
     else{
         int nq = addnew(maxlen[p]+);
         for(int i=;i<;i++) son[nq][i] = son[q][i];
         fa[nq] = fa[q]; fa[q] = fa[np] = nq;
         while(p && son[p][x-'a'] == q) son[p][x-'a'] = nq,p = fa[p];
         return np;
     }
     }
 }

 void dfs(int now,int cnt){
     int flag = ;
     for(int i=;i<;i++){
     if(!son[now][i]) continue;
     dfs(son[now][i],cnt+); flag = ;
     break;
     }
     if(!flag){cout<<str.length()-cnt+<<endl;}
 }

 void init(){
     for(int i=;i<=num;i++) memset(son[i],,sizeof(son[i]));
     for(int i=;i<=num;i++) fa[i] = maxlen[i] = ;
     root = ; num = ;
 }

 void work(){
     int lst = addnew();root = lst;
     for(int i=;i<str.length();i++)
     lst = ins(str[i],lst);
     dfs(root,);
 }

 int main(){
     ios::sync_with_stdio(false);
     cin.tie();
     int Tmp; cin >> Tmp;
     while(Tmp--){
     init();
     cin >> str;
     str+=str;
     work();
     }
     return ;
 }