[BZOJ]1014 火星人prefix(JSOI2008)

#include 
#include 
#include 
#define l(a) son[a][0]
#define r(a) son[a][1]
#define rt (l(rtfa))
#define rtfa (MN-1)
#define MN 100005
#define ll long long
using namespace std;
int siz[MN],son[MN][2],cr[MN],fa[MN];
char c[MN];
int din,n,m;
ll hs[MN];

inline int read()
{
    int n=0,f=1; char c=getchar();
    while (c‘0‘ || c>‘9‘) {if(c==‘-‘)f=-1; c=getchar();}
    while (c>=‘0‘ && c‘9‘) {n=n*10+c-‘0‘; c=getchar();}
    return n*f;
}

inline ll mi(ll x,int y)
{
    register ll z=1;
    for (;y;y>>=1,x=x*x) if (y&1) z=z*x;
    return z;
}
inline void update(int x)
{
    siz[x]=siz[l(x)]+siz[r(x)]+1;
    hs[x]=(hs[l(x)]*101+cr[x])*mi(101,siz[r(x)])+hs[r(x)];
}

void rotate(int x)
{
    register int y,z,l,r;
    y=fa[x]; z=fa[y]; l=r(y)==x; r=l^1;
    fa[y]=x; fa[x]=z; fa[son[x][r]]=y;
    son[z][r(z)==y]=x; son[y][l]=son[x][r]; son[x][r]=y;
    update(y);
}
void splay(int x,int rf)
{
    register int y,z;
    for (;fa[x]!=rf;rotate(x))
        if (fa[y=fa[x]]!=rf) z=fa[y],rotate(r(z)==y^r(y)==x?x:y);
    update(x);
}

void getins(int &x,int fat,int y,char z)
{
    if (!x) {x=++din; cr[x]=z; fa[x]=fat; splay(x,rtfa); return;}
    if (y>=siz[l(x)]+1) getins(r(x),x,y-siz[l(x)]-1,z);
    else getins(l(x),x,y,z);
}
void getsiz(int x,int y,int rtf)
{
    if (y==siz[l(x)]+1) {splay(x,rtf); return;}
    else if (y>siz[l(x)]+1) getsiz(r(x),y-siz[l(x)]-1,rtf);
    else getsiz(l(x),y,rtf);
}
void getitv(int L,int R) {R+=2; getsiz(rt,L,rtfa); getsiz(rt,R,rt);}

void build(int &x,int fat,int L,int R)
{
    if (L>R) return;
    int mid=L+R>>1;
    x=++din; cr[x]=c[mid]; fa[x]=fat;
    build(l(x),x,L,mid-1); build(r(x),x,mid+1,R);
    update(x);
}

int main()
{
    char g[2],z[2];
    register int x,y,L,R;
    register ll lx,ly;
    scanf("%s",c+1);
    n=strlen(c+1); m=read();
    c[0]=c[n+1]=0;
    build(rt,rtfa,0,n+1);    
    while (m--)
    {
        scanf("%s",g);
        if (g[0]==‘Q‘)
        {
            x=read(); y=read();
            if (x>y) swap(x,y);
            for (L=0,R=n-y+1;LR;)
            {
                int mid=L+R+1>>1;
                getitv(x,x+mid-1); lx=hs[l(r(rt))];    
                getitv(y,y+mid-1); ly=hs[l(r(rt))];                    
                if (lx==ly) L=mid; else R=mid-1;
            }
            printf("%d\n",L);
        }
        else if (g[0]==‘R‘)
        {
            x=read(); scanf("%s",z); getsiz(rt,x+1,rtfa);
            cr[rt]=z[0]; update(rt);
        }
        else if (g[0]==‘I‘) {x=read(); ++n; scanf("%s",z); getins(rt,rtfa,x+1,z[0]);}
    }
}