【BZOJ 3756】—Pty的字符串(广义后缀自动机)

传送门

由于给出TrieTrie
直接跑广义SamSam即可

相当于模板了

注意广义SamSam模板的几处特判 (虽然并不知道是否真的有用)

#include<bits/stdc++.h>
using namespace std;
const int RLEN=1<<20|1;
inline char gc(){
    static char ibuf[RLEN],*ib,*ob;
    (ob==ib)&&(ob=(ib=ibuf)+fread(ibuf,1,RLEN,stdin));
    return (ob==ib)?EOF:*ib++;
}
#define gc getchar
inline int read(){
    char ch=gc();
    int res=0,f=1;
    while(!isdigit(ch))f^=ch=='-',ch=gc();
    while(isdigit(ch))res=(res+(res<<2)<<1)+(ch^48),ch=gc();
    return f?res:-res;
}
#define ll long long
#define re register
#define pii pair<int,int>
#define pic pair<int,char>
#define fi first
#define se second
#define pb push_back
#define cs const
#define bg begin
#define poly vector<int>
#define chemx(a,b) ((a)<(b)?(a)=(b):0)
#define chemn(a,b) ((a)>(b)?(a)=(b):0)
cs int N=800006;
namespace Sam{
	int fail[N<<1],nxt[N<<1][26],len[N<<1],siz[N],tot;
	inline void init(){
		tot=1;
	}
	inline int insert(int last,int c){
		if(nxt[last][c]&&len[nxt[last][c]]==len[last]+1)return nxt[last][c];//
		int cur=++tot,fg=0,p=last;len[cur]=len[p]+1;
		for(;p&&!nxt[p][c];p=fail[p])nxt[p][c]=cur;
		if(!p)fail[cur]=1;
		else{
			int q=nxt[p][c];
			if(len[q]==len[p]+1)fail[cur]=q;
			else{
				if(len[cur]==len[p]+1)fg=1;//
				int clo=++tot;
				len[clo]=len[p]+1,fail[clo]=fail[q];
				memcpy(nxt[clo],nxt[q],sizeof(nxt[q]));
				for(;p&&nxt[p][c]==q;p=fail[p])nxt[p][c]=clo;
				fail[q]=fail[cur]=clo;
			}
		}
		return fg?tot:cur;//
	}
	ll f[N<<1];
	int rk[N<<1],buc[N<<1];
	inline void buc_sort(){
		for(int i=1;i<=tot;i++)buc[len[i]]++;
		for(int i=1;i<=tot;i++)buc[i]+=buc[i-1];
		for(int i=1;i<=tot;i++)rk[buc[len[i]]--]=i;
		for(int i=tot;i;i--)siz[fail[rk[i]]]+=siz[rk[i]];
		for(int i=1;i<=tot;i++)f[i]=1ll*siz[i]*(len[i]-len[fail[i]]);
		for(int i=1;i<=tot;i++)f[rk[i]]+=f[fail[rk[i]]];
	}
	inline ll calc(char *s){
		ll res=0;int p=1,mxlen=0;
		for(int i=1,l=strlen(s+1);i<=l;i++){
			int c=s[i]-'a';
			while(p&&!nxt[p][c])p=fail[p],mxlen=len[p];
			if(!p)p=1,mxlen=0;
			else{
				p=nxt[p][c],mxlen++;
				res+=f[fail[p]]+1ll*siz[p]*(mxlen-len[fail[p]]);
			}
		}
		return res;
	}
}
namespace Trie{
	int nxt[N][26],siz[N],tot,pos[N];
	inline int insert(int u,int c){
		return nxt[u][c]?nxt[u][c]:(nxt[u][c]=++tot);
	}
	queue<int> q;
	inline void build(){
		q.push(0),pos[0]=1;
		while(!q.empty()){
			int p=q.front();q.pop();
			for(int c=0;c<26;c++){
				int v=nxt[p][c];
				if(v){
					pos[v]=Sam::insert(pos[p],c);
					Sam::siz[pos[v]]+=siz[v];
					q.push(v);
				}
			}
		}
	}
}
char s[N*10];
int n,pos[N];
int main(){
	Sam::init();
	n=read();
	for(int i=2;i<=n;i++){
		int fa=read();scanf("%s",s+1);
		int c=s[1]-'a';
		pos[i]=Trie::insert(pos[fa],c);
		Trie::siz[pos[i]]++;
	}
	Trie::build(),Sam::buc_sort();
	scanf("%s",s+1);
	cout<<Sam::calc(s)<<'
';
}
原文地址:https://www.cnblogs.com/stargazer-cyk/p/12328447.html