[AHOI2006]文本编辑器editor

一不小心又开启了每天昏迷24个小时的状态，脑子不清醒的时候就该去看动画片。

只需要记录光标的位置即可，剩下的就是Splay的经典操作了，不多说了，我只是为了测试模板。

#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <queue>
#include <cmath>
#include <stack>
#include <map>

#pragma comment(linker, "/STACK:1024000000");
#define EPS (1e-8)
#define LL long long
#define ULL unsigned long long
#define _LL __int64
#define _INF 0x3f3f3f3f
#define Mod 9999991

using namespace std;

const int MAXN = 3001000;

struct N
{
    //info
    int son[2],pre;

    //data
    char data;
    int mark;
    int ls,rs,s;
} st[MAXN];

int Top;

char s[MAXN];

void Push_Down(int root)
{
    if(st[root].mark == 1)
    {
        st[root].mark = 0;

        if(st[root].son[0] != -1)
            st[st[root].son[0]].mark ^= 1;
        if(st[root].son[1] != -1)
            st[st[root].son[1]].mark ^= 1;

        int temp = st[root].ls;
        st[root].ls = st[root].rs;
        st[root].rs = temp;

        temp = st[root].son[0];
        st[root].son[0] = st[root].son[1];
        st[root].son[1] = temp;
    }
}

void Updata(int root)
{
     st[root].ls = 0,st[root].rs = 0;

     if(st[root].son[0] != -1)
     {
         st[root].ls = st[st[root].son[0]].s;
     }

     if(st[root].son[1] != -1)
     {
         st[root].rs = st[st[root].son[1]].s;
     }

     st[root].s = st[root].ls + st[root].rs + 1;
}

void Init(int &root,int s,int e,int pre,char *S)
{
     if(s > e)
        return ;
     int mid = (s+e)>>1;
     root = Top++;
     st[root].son[0] = -1,st[root].son[1] = -1;
     st[root].pre = pre;
     st[root].data = S[mid];
     st[root].mark = 0;
     Init(st[root].son[0],s,mid-1,root,S);
     Init(st[root].son[1],mid+1,e,root,S);

     Updata(root);
}

void Rotate(int root,int dir)
{
    st[st[root].pre].son[dir] = st[root].son[1^dir];
    st[root].son[1^dir] = st[root].pre;

    if(st[st[st[root].pre].pre].son[0] == st[root].pre)
        st[st[st[root].pre].pre].son[0] = root;
    else
        st[st[st[root].pre].pre].son[1] = root;
    int temp = st[root].pre;
    st[root].pre = st[st[root].pre].pre;
    st[temp].pre = root;

    if(st[temp].son[dir] != -1)
        st[st[temp].son[dir]].pre = temp;
    Updata(temp);
    Updata(root);
}

int Splay(int root,int goal)
{
    while(st[root].pre != goal)
    {
        Rotate(root,(st[st[root].pre].son[0] == root ? 0 : 1));
    }

    return root;
}

int Search_Site(int root,int site)
{
    do
    {
        Push_Down(root);

        if(st[root].ls + 1 == site)
            return root;
        if(st[root].ls + 1 < site)
        {
            site = site - st[root].ls - 1;
            root = st[root].son[1];
        }
        else
            root = st[root].son[0];
    }while(1);
}

void Insert(int &R,int site,int len,char *s)
{
    R = Splay(Search_Site(R,site+1),0);
    R = Splay(Search_Site(R,site),0);

    int tr = -1;
    Init(tr,1,len,st[R].son[1],s);
    st[st[R].son[1]].son[0] = tr;
    Updata(st[R].son[1]);
    Updata(R);
}

void Delete(int &R,int site,int len)
{
    R = Splay(Search_Site(R,site+len+1),0);
    R = Splay(Search_Site(R,site),0);

    st[st[R].son[1]].son[0] = -1;
    Updata(st[R].son[1]);
    Updata(R);
}

void Rotate(int &R,int site,int len)
{
    R = Splay(Search_Site(R,site+len+1),0);
    R = Splay(Search_Site(R,site),0);

    st[st[st[R].son[1]].son[0]].mark ^= 1;
}

void Get(int &R,int site)
{
    printf("%c\n",st[Search_Site(R,site+1)].data);
}

int main()
{
    char S[5];
    S[1] = '*',S[2] = '*',S[3] = '\n';

    int n;

    int root;

    int len;

    char order[10];

    int site;

    while(scanf("%d",&n) != EOF)
    {
        root = -1,Top = 1;

        Init(root,1,2,0,S);

        st[0].son[0] = root,st[0].son[1] = -1;

        site = 1;

        while(n--)
        {
            scanf("%s",order);

            if(strcmp(order,"Insert") == 0)
            {
                scanf("%d%*c",&len);
                gets(s+1);
                Insert(root,site,len,s);
            }
            else if(strcmp(order,"Move") == 0)
            {
                scanf("%d",&len);
                site = len+1;
            }
            else if(strcmp(order,"Delete") == 0)
            {
                scanf("%d",&len);
                Delete(root,site,len);
            }
            else if(strcmp(order,"Rotate") == 0)
            {
                scanf("%d",&len);
                Rotate(root,site,len);
            }
            else if(strcmp(order,"Get") == 0)
            {
                Get(root,site);
            }
            else if(strcmp(order,"Prev") == 0)
            {
                site--;
            }
            else if(strcmp(order,"Next") == 0)
            {
                site++;
            }
        }
    }

    return 0;
}

[AHOI2006]文本编辑器editor