题目传送门

和上一篇题目几乎一样，不过还是这道题良心！bzoj好！poj慢到出*

splay大法好! 两次AC不卡常！

#pragma GCC opitmize("O3")
#pragma G++ opitmize("O3")
#include
#include
#include
#define N 400010
#define LL long long
#define son(x) (x==ch[f[x]][1]) 
using namespace std;
LL h[N],bas[N]={1};
int f[N],ch[N][2],sz[N],v[N];
int n,m,cnt=0,rt=0,q;
inline int newnode(int k){++cnt; h[cnt]=v[cnt]=k; sz[cnt]=1;return cnt;
}
inline void ps(int x){ sz[x]=sz[ch[x][0]]+sz[ch[x][1]]+1;h[x]=(h[ch[x][0]]*131+v[x])*bas[sz[ch[x][1]]]+h[ch[x][1]];
}
inline void rot(int x){int p=f[x],g=f[p],d=son(x);ch[p][d]=ch[x][!d]; f[ch[p][d]]=p;ch[x][!d]=p; f[p]=x; f[x]=g;if(g) ch[g][p==ch[g][1]]=x; ps(p); ps(x);
}
inline void splay(int x,int r=0){for(int p;(p=f[x])!=r;rot(x))if(f[p]!=r && son(x)==son(p)) rot(p);if(!r) rt=x;
}
inline int select(int k,int x=rt){for(int w;;){w=sz[ch[x][0]]+1;if(w==k) return x;if(k<w) x=ch[x][0];else k-=w,x=ch[x][1];}
}
inline int gRank(int k,int x=rt){int r=1;for(;x;){if(v[x]>=k) x=ch[x][0];else{ r+=sz[ch[x][0]]+1; x=ch[x][1]; }}return r;
}
inline int rank(int x){int r=sz[ch[x][0]]+1;for(;x;x=f[x])if(son(x)) r+=sz[ch[f[x]][0]]+1;return r;
}
inline void Llink(int x,int v){ f[ch[x][0]=v]=x; ps(x); }
inline void Rlink(int x,int v){ f[ch[x][1]=v]=x; ps(x); }
inline LL gH(int x,int len){splay(select(x-1));splay(select(x+len),rt);return h[ch[ch[rt][1]][0]];
}
char c[100010],o[3];
int main(){
    scanf("%s%d",c,&n); m=strlen(c); rt=newnode(0);for(int i=1;i<100010;++i) bas[i]=bas[i-1]*131;for(int i=0;i<m;++i){ Llink(newnode(c[i]),rt); rt=cnt; }Llink(newnode(0),rt); rt=cnt;for(int x,y;n--;){scanf("%s",o);if(*o=='I'){scanf("%d%s",&x,o);splay(select(x+2)); splay(select(x+1),rt);Rlink(ch[rt][0],newnode(*o));ps(rt);} else if(*o=='R'){ scanf("%d%s",&x,o);splay(select(x+1)); v[rt]=*o; ps(rt);} else {scanf("%d%d",&x,&y); ++x; ++y;int a=x,b=y;if(x==y){printf("%d\n",sz[rt]-max(a,b));continue;}int l=0,r=sz[rt]-max(a,b);for(int M;l<r;){M=l+r+1>>1;if(gH(a,M)==gH(b,M)) l=M;else r=M-1;}printf("%d\n",l);}}