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 ;
}
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