bzoj千题计划106：bzoj1014 [JSOI2008]火星人prefix

#include<cstdio>
#include<cstring>
#include<iostream>

#define L 100001

typedef unsigned long long ULL;

using namespace std;

char s[L+4];

int tot,root;
int fa[L+4],ch[L+4][2],siz[L+4],key[L+4];
ULL has[L+4];

ULL bit[L+4];

int len;

void read(int &x)
{
    x=0; char c=getchar();
    while(!isdigit(c)) c=getchar();
    while(isdigit(c)) { x=x*10+c-‘0‘; c=getchar();} 
}

void update(int x)
{
    siz[x]=siz[ch[x][0]]+siz[ch[x][1]]+1;
    has[x]=has[ch[x][0]]*bit[siz[ch[x][1]]+1]+key[x]*bit[siz[ch[x][1]]]+has[ch[x][1]];
}

void build(int l,int r,int f)
{
    if(l>r) return;
    int mid=l+r>>1;
    ch[f][mid>f]=mid;
    fa[mid]=f;
    siz[mid]=1; key[mid]=s[mid]-‘a‘+1;
    build(l,mid-1,mid);
    build(mid+1,r,mid);
    update(mid);
}

int find(int x)
{
    int now=root;
    while(1)
    {
        if(siz[ch[now][0]]>=x) now=ch[now][0];
        else
        {
            x-=siz[ch[now][0]];
            if(x==1) return now;
            x--; now=ch[now][1];
        }
    }
}

int findsuf(int x)
{
    int now=ch[x][1];
    while(ch[now][0]) now=ch[now][0];
    return now;
}

void rotate(int x,int &goal)
{
    int y=fa[x],z=fa[y],k=ch[y][1]==x;
    if(y!=goal) ch[z][ch[z][1]==y]=x;
    else goal=x;
    ch[y][k]=ch[x][k^1]; ch[x][k^1]=y; 
    fa[x]=z; fa[y]=x; fa[ch[y][k]]=y;
    update(y);
}

bool getson(int x)
{
    return ch[fa[x]][1]==x;
}

void splay(int x,int &goal)
{
    int y;
    while(x!=goal)
    {
        y=fa[x];
        if(y==goal) rotate(x,goal);
        else
        {
            if(getson(x)^getson(y)) rotate(x,goal);
            else rotate(y,goal);
            rotate(x,goal);
        }
        update(x);
    }

}

ULL query(int l,int r)
{
    if(r==len+1)
    {
        int t1=find(l-1);
        splay(t1,root);
        return has[ch[root][1]];
    }
    int tl=find(l-1),tr=find(r+1);
    splay(tl,root);
    splay(tr,ch[root][1]);
    return has[ch[tr][0]];
}

int main()
{
    //freopen("bzoj_1014.in","r",stdin);
    //freopen("bzoj_1014.out","w",stdout);
    scanf("%s",s+2); len=strlen(s+2);
    int m; read(m);
    bit[0]=1;  for(int i=1;i<L;++i) bit[i]=bit[i-1]*27;
    build(1,len+1,0);
    root=len+2>>1;
    char c[3]; int x,y;
    int l,r,mid,ans;
     tot=len+1;
    while(m--)
    {
        scanf("%s",c); 
        if(c[0]==‘Q‘)
        {
            read(x); read(y);
            x++; y++;
            ans=0; l=0; r=min(len+1-x+1,len+1-y+1); 
            while(l<=r)
            {
                mid=l+r>>1;
                if(query(x,x+mid-1)!=query(y,y+mid-1)) r=mid-1;
                else l=mid+1,ans=mid;
            }
            cout<<ans<<‘\n‘;
        }
        else if(c[0]==‘R‘)
        {
            read(x); scanf("%s",c);
            x++;
            x=find(x); 
            splay(x,root);
            key[x]=c[0]-‘a‘+1;        
        }
        else
        {
            read(x); scanf("%s",c);
            x++;
            x=find(x); splay(x,root);
            y=findsuf(x); 
            if(y)
            {
                splay(y,ch[x][1]);
                ch[y][0]=++tot; fa[tot]=y;
                key[tot]=has[tot]=c[0]-‘a‘+1;
                siz[tot]=1;
                update(y); update(x);
            }
            else
            {
                ch[x][1]=++tot; fa[tot]=x;
                key[tot]=has[tot]=c[0]-‘a‘+1;
                siz[tot]=1;
                update(x);
            }
            len++;
        }
    }
}