BZOJ2555 SubString（后缀自动机+LCT）

　　询问串放在SAM上不跳fail跑到的节点的|right|即为答案。用LCT维护parent树即可。可以直接维护子树信息，也可以转化为路径加。注意强制在线所使用的mask是作为参数传进去的。

#include<iostream> 
#include<cstdio>
#include<cmath>
#include<cstdlib>
#include<cstring>
#include<algorithm>
using namespace std;
#define ll long long
#define N 1300010
#define lson tree[k].ch[0]
#define rson tree[k].ch[1]
#define lself tree[tree[k].fa].ch[0]
#define rself tree[tree[k].fa].ch[1]
char getc(){char c=getchar();while ((c<'A'||c>'Z')&&(c<'a'||c>'z')&&(c<'0'||c>'9')) c=getchar();return c;}
int gcd(int n,int m){return m==0?n:gcd(m,n%m);}
int read()
{
	int x=0,f=1;char c=getchar();
	while (c<'0'||c>'9') {if (c=='-') f=-1;c=getchar();}
	while (c>='0'&&c<='9') x=(x<<1)+(x<<3)+(c^48),c=getchar();
	return x*f;
}
int Q,n,m,cnt=1,last=1,son[N][26],fail[N],len[N],mask;
char s[N],t[N];
struct data{int ch[2],fa,rev,s,sv,x; 
}tree[N];
void up(int k){tree[k].s=tree[k].sv+tree[lson].s+tree[rson].s+tree[k].x;}
void rev(int k){if (k) swap(lson,rson),tree[k].rev^=1;}
void down(int k){if (tree[k].rev) rev(lson),rev(rson),tree[k].rev=0;}
int whichson(int k){return rself==k;}
bool isroot(int k){return lself!=k&&rself!=k;}
void push(int k){if (!isroot(k)) push(tree[k].fa);down(k);}
void move(int k)
{
	int fa=tree[k].fa,gf=tree[fa].fa,p=whichson(k);
	if (!isroot(fa)) tree[gf].ch[whichson(fa)]=k;tree[k].fa=gf;
	tree[fa].ch[p]=tree[k].ch[!p],tree[tree[k].ch[!p]].fa=fa;
	tree[k].ch[!p]=fa,tree[fa].fa=k;
	up(fa),up(k);
}
void splay(int k) 
{
	push(k);
	while (!isroot(k))
	{
		int fa=tree[k].fa;
		if (!isroot(fa))
			if (whichson(fa)^whichson(k)) move(k);
			else move(fa);
		move(k);
	}
}
void access(int k)
{
	for (int t=0;k;t=k,k=tree[k].fa)
	{
		splay(k);
		tree[k].sv+=tree[rson].s-tree[t].s; 
		rson=t;
		up(k);
	}
}
void makeroot(int k){access(k),splay(k),rev(k);}
void link(int x,int y){makeroot(x);access(y),splay(y);tree[x].fa=y;tree[y].sv+=tree[x].s;up(y);}
void cut(int x,int y){makeroot(x),access(y),splay(y);tree[y].ch[0]=tree[x].fa=0;up(y);}
int query(int k){if (!k) return 0;makeroot(1);access(k),splay(k);return tree[k].s-tree[lson].s;}
void decode(int mask)
{
	for (int j=0;j<m;j++)
	{
		mask=(mask*131+j)%m;
		char u=t[j];t[j]=t[mask];t[mask]=u;
	}
}
void relink(int x,int y)
{
	if (fail[x]) cut(x,fail[x]);
	fail[x]=y;link(x,y);
}
void ins(int c)
{ 
	int x=++cnt,p=last;len[x]=len[p]+1;last=x;tree[x].x=tree[x].s=1;
	while (!son[p][c]&&p) son[p][c]=x,p=fail[p];
	if (!p) relink(x,1);
	else
	{
		int q=son[p][c];
		if (len[p]+1==len[q]) relink(x,q);
		else
		{
			int y=++cnt;
			len[y]=len[p]+1;
			memcpy(son[y],son[q],sizeof(son[q]));
			relink(y,fail[q]);
			relink(q,y);
			relink(x,y);
			while (son[p][c]==q) son[p][c]=y,p=fail[p];
		}
	}
}
int run(char *s)
{
	int k=1;
	for (int i=0;i<m;i++) k=son[k][s[i]-'A'];
	return k;
}
int main()
{
#ifndef ONLINE_JUDGE
	freopen("a.in","r",stdin);
	freopen("a.out","w",stdout);
	const char LL[]="%I64d\n";
#else
	const char LL[]="%lld\n";
#endif
	Q=read();scanf("%s",s);n=strlen(s);
	for (int i=0;i<n;i++) ins(s[i]-'A');
	while (Q--)
	{
		scanf("%s",t);
		if (t[0]=='A')
		{
			scanf("%s",t);m=strlen(t);
			decode(mask);
			for (int i=0;i<m;i++) ins(t[i]-'A');
		}
		else
		{
			scanf("%s",t);m=strlen(t);
			decode(mask);
			int ans=query(run(t));
			printf("%d\n",ans);
			mask^=ans;
		}
	}
	return 0;
}