【LOJ#6198】—谢特(后缀数组+01Trie)

传送门

建出后缀数组按照heightheight合并连通块
维护01Trie01Trie合并,启发式询问即可

#include<bits/stdc++.h>
using namespace std;
const int RLEN=(1<<20)|5;
inline char gc(){
	static char ibuf[RLEN],*ib,*ob;
	(ib==ob)&&(ob=(ib=ibuf)+fread(ibuf,1,RLEN,stdin));
	return (ib==ob)?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 pb push_back
#define re register
#define fi first
#define se second
#define pii pair<int,int>
#define cs const
#define bg begin
#define ll long long

template<class tp>inline void chemx(tp &a,tp b){a<b?a=b:0;}
template<class tp>inline void chemn(tp &a,tp b){a>b?a=b:0;}
cs int N=100005;
char xxx;
namespace Trie{
	cs int M=N*30;
	int tot,son[M][2],siz[M];
	void insert(int &u,int k,int dep){
		if(!u)u=++tot;siz[u]++;
		if(dep<0)return;
		insert(son[u][(k>>dep)&1],k,dep-1);
	}
	int query(int &u,int k,int dep){
		if(dep<0)return 0;
		int t=(k>>dep)&1;
		if(siz[son[u][t^1]])return (1<<dep)+query(son[u][t^1],k,dep-1);
		else return query(son[u][t],k,dep-1);
	}
	void merge(int &u,int r1,int r2){
		if(!r1||!r2){u=r1+r2;return;}
		u=r1,siz[u]=siz[r1]+siz[r2];
		merge(son[u][0],son[r1][0],son[r2][0]);
		merge(son[u][1],son[r1][1],son[r2][1]);
	}
}
int ans;
namespace Sa{
	int sa[N],sa2[N],s[N],rk[N],buc[N],ht[N];
	int n,m;
	inline void buc_sort(){
		for(int i=1;i<=m;i++)buc[i]=0;
		for(int i=1;i<=n;i++)buc[rk[sa2[i]]]++;
		for(int i=1;i<=m;i++)buc[i]+=buc[i-1];
		for(int i=n;i>=1;i--)sa[buc[rk[sa2[i]]]--]=sa2[i];
	}
	inline void build(char *ss,int _n){
		n=_n;m=27;
		for(int i=1;i<=n;i++)s[i]=ss[i]-'a'+1,rk[i]=s[i],sa2[i]=i;
		buc_sort();
		for(int pos=0,i=1;i<=n&&pos<n;i<<=1){
			pos=0;
			for(int j=n-i+1;j<=n;j++)sa2[++pos]=j;
			for(int j=1;j<=n;j++)if(sa[j]>i)sa2[++pos]=sa[j]-i;
			buc_sort();
			swap(rk,sa2);
			pos=1,rk[sa[1]]=1;
			for(int j=2;j<=n;j++)
			rk[sa[j]]=(sa2[sa[j]]==sa2[sa[j-1]]&&sa2[sa[j]+i]==sa2[sa[j-1]+i])?pos:++pos;
			m=pos;
		}
		for(int i=1,j,k=0;i<=n;ht[rk[i++]]=k)
		for(k?k--:0,j=sa[rk[i]-1];s[j+k]==s[i+k];k++);
	}
	int fa[N],rt[N],w[N];
	int p[N];
	vector<int> st[N];
	inline bool comp(int a,int b){
		return ht[a]>ht[b];
	}
	inline int find(int x){
		return fa[x]==x?x:fa[x]=find(fa[x]);
	}
	inline void merge(int x,int y,int k){
		int f1=find(x),f2=find(y);
		if(st[f1].size()>st[f2].size())swap(f1,f2);
		fa[f1]=f2;int res=0;
		for(int &x:st[f1]){
			chemx(res,Trie::query(rt[f2],w[x],18));
			st[f2].pb(x);
		}
		Trie::merge(rt[f2],rt[f1],rt[f2]);
		chemx(ans,res+k);
	}
	inline void solve(){
		for(int i=1;i<=n;i++)fa[i]=i,st[i].pb(i),Trie::insert(rt[i],w[i],18);
		for(int i=2;i<=n;i++)p[i-1]=i;
		sort(p+1,p+n,comp);
		for(int i=1;i<n;i++){
			int pos=p[i];
			merge(pos,pos-1,ht[pos]);
		}
		cout<<ans;
	}
}
int n;
char s[N];
char yyy;
int main(){
	n=read();
	scanf("%s",s+1);
	Sa::build(s,n);
	for(int i=1;i<=n;i++)Sa::w[Sa::rk[i]]=read();
	Sa::solve();
}
posted @ 2019-10-19 00:01  Stargazer_cykoi  阅读(158)  评论(0编辑  收藏  举报