bzoj1014: [JSOI2008]火星人prefix Hash+Splay

#include<bits/stdc++.h>
#define L(t) (t)->c[0]
#define R(t) (t)->c[1]
#define Z(t) (L(t)->s+1)
#define N 100010
#define M (l+r>>1)
typedef unsigned long long ull;
ull a[N];
struct node{
	int v,s;
	ull u;
	node* c[2];
	node(int v,node* x,node* y)
	:v(v),s(0),u(v){
		c[0]=x,c[1]=y;
	}
}*null=new node(0,0,0),*root;
node* update(node* t){
	t->s=R(t)->s+Z(t);
	t->u=L(t)->u+t->v
	*a[L(t)->s]+R(t)->u*a[Z(t)];
	return t;
}
void link(bool i,node*& t,node*& s){
	node* d=t->c[i];
	t->c[i]=s;
	s=update(t);
	t=d;
}
node* splay(int v,node*& t=root){
	node* d[]={null,null};
	while(v!=Z(t)){
		bool i=v>Z(t);
		v-=i*Z(t);
		if(v!=Z(t->c[i])
		&&i==v>Z(t->c[i])){
			v-=i*Z(t->c[i]);
			link(i,t,t->c[i]->c[i^1]);
		}
		link(i,t,d[i]);
	}
	for(int i=0;i!=2;++i){
		node* s=t->c[i^1];
		while(d[i]!=null)
			link(i,d[i],s);
		t->c[i^1]=s;
	}
	return update(t);
}
node* build(char* v,int l,int r){
	return l>r?null
	:update(new node(v[M],
	build(v,l,M-1),
	build(v,M+1,r)));
}
node*& interval(int l,int r){
	splay(l);
	splay(r-l+2,R(root));
	return L(R(root));
}
int n;
bool check(int v,int x,int y){
	ull u=interval(x,x+v-1)->u;
	return u==interval(y,y+v-1)->u;
}
char v[N];
int main(){
	a[0]=1;
	for(int i=1;i!=N;++i)
		a[i]=a[i-1]*23;
	int m,x,y;
	char s[2],d[2];
	scanf("%s%d",v+1,&m);
	n=strlen(v+1);
	root=build(v,0,n+1);
	while(m--){
		scanf("%s%d",s,&x);
		if(*s==‘Q‘){
			scanf("%d",&y);
			int l=0,r=n-std::max(x,y)+1;
			while(l!=r){
				int mid=l+r+1>>1;
				if(check(mid,x,y))
					l=mid;
				else r=mid-1;
			}
			printf("%d\n",l);
		}
		if(*s==‘R‘){
			scanf("%s",d);
			splay(x+1)->v=*d;
		}
		if(*s==‘I‘&&++n){
			scanf("%s",d);
			interval(x+1,x)=update(
			new node(*d,null,null));
		}
	}
}