HYSBZ 1269文本编辑器 splay

比较基本的操作。

#include<map>
#include<queue>
#include<stack>
#include<cmath>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#define INF 99999999
#define ll __int64
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define key_value ch[ch[root][1]][0]
using namespace std;
const int MAXN = ;
int pre[MAXN],rev[MAXN],siz[MAXN],ch[MAXN][],s[MAXN],tot1,tot2,root;
int n;
char a[MAXN],key[MAXN];
void Treavel(int x)
{
    if(x)
    {
        Treavel(ch[x][]);
        printf("结点%2d:左儿子 %2d 右儿子 %2d 父结点 %2d size=%2d key=%2c rev=%2d pre=%2d\n",x,ch[x][],ch[x][],pre[x],siz[x],key[x],rev[x],pre[x]);
        Treavel(ch[x][]);
    }
}
void debug()
{
    printf("root:%d\n",root);
    Treavel(root);
}
void Newnode(int &rt,int pa,int k)
{
    if(tot2){
        rt = s[tot2--];
    }
    else {
        rt = ++tot1;
    }
    pre[rt] = pa;
    siz[rt] = ;
    key[rt] = k;
    rev[rt] = ;
    ch[rt][] = ch[rt][] = ;
}
void pushup(int rt)
{
    siz[rt] = siz[ch[rt][]] + siz[ch[rt][]] + ;
}
void updata_rev(int rt)
{
    if(!rt)
        return;
    rev[rt] ^= ;
    swap(ch[rt][],ch[rt][]);
}
void pushdown(int rt)
{
    if(rev[rt]){
        updata_rev(ch[rt][]);
        updata_rev(ch[rt][]);
        rev[rt] = ;
    }
}
void build(int &rt,int l,int r,int pa)
{
    if(l > r)
        return ;
    int m = (l+r)/;
    Newnode(rt,pa,a[m]);
    build(ch[rt][],l,m-,rt);
    build(ch[rt][],m+,r,rt);
    pushup(rt);
}
void Init()
{
    root = tot1 = tot2 = ;
    key[root] = pre[root] = rev[root] = siz[root] = ;
    ch[root][] = ch[root][] = ;
    Newnode(root,,);
    Newnode(ch[root][],root,);
    pushup(ch[root][]);
    pushup(root);
}
void Rotate(int rt,int kind)
{
    int y = pre[rt];
    pushdown(y);
    pushdown(rt);
    ch[y][!kind] = ch[rt][kind];
    pre[ch[rt][kind]] = y;
    if(pre[y]){
        ch[pre[y]][ch[pre[y]][]==y] = rt;
    }
    pre[rt] = pre[y];
    ch[rt][kind] = y;
    pre[y] = rt;
    pushup(y);
}
void splay(int rt,int goal)
 {
    pushdown(rt);
    while(pre[rt] != goal)
    {
        if(pre[pre[rt]] == goal){
            pushdown(pre[rt]);
            pushdown(rt);
            Rotate(rt,ch[pre[rt]][]==rt);
        }
        else {
            pushdown(pre[pre[rt]]);
            pushdown(pre[rt]);
            pushdown(rt);
            int y = pre[rt];
            int kind = ch[pre[y]][]==y;
            if(ch[y][kind] == rt){
                Rotate(rt,!kind);
                Rotate(rt,kind);
            }
            else {
                Rotate(y,kind);
                Rotate(rt,kind);
            }
        }
    }
    if(goal == )
        root = rt;
    pushup(rt);
}
int Get_kth(int rt,int k)
{
    pushdown(rt);
    int t = siz[ch[rt][]] + ;
    if(t == k){
        return rt;
    }
    else if(t > k){
        return Get_kth(ch[rt][],k);
    }
    else {
        return Get_kth(ch[rt][],k-t);
    }
}
int Get_next(int rt)
{
    pushdown(rt);
    int tmp = ch[rt][];
    while(ch[tmp][]){
        tmp = ch[tmp][];
        pushdown(tmp);
    }
    return tmp;
}
int Get_pre(int rt)
{
    pushdown(rt);
    int tmp = ch[rt][];
    while(ch[tmp][]){
        tmp = ch[tmp][];
        pushdown(tmp);
    }
    return tmp;
}
void erase(int rt)
{
    if(!rt)
        return;
    s[++tot2] = rt;
    erase(ch[rt][]);
    erase(ch[rt][]);
}
int main()
{
    int i,j;
    while(~scanf("%d",&n))
    {
        Init();
        char c[];
        //debug();
        while(n--)
        {
            scanf("%s",c);
            if(c[] == 'I'){
                int len;
                scanf("%d",&len);
                getchar();
                gets(a);
                splay(Get_next(root),root);
                build(key_value,,len-,ch[root][]);
                pushup(ch[root][]);
                pushup(root);
                //debug();
            }
            else if(c[] == 'D'){
                int x;
                scanf("%d",&x);
                int ret = siz[ch[root][]] + ;
                splay(Get_kth(root,ret+x+),root);
                erase(key_value);
                pre[key_value] = ;
                key_value = ;
                pushup(ch[root][]);
                pushup(root);
                //debug();
            }
            else if(c[] == 'R'){
                int x;
                scanf("%d",&x);
                int ret = siz[ch[root][]] + ;
                splay(Get_kth(root,ret+x+),root);
                updata_rev(key_value);
                pushup(ch[root][]);
                pushup(root);
                //debug();
            }
            else if(c[] == 'G'){
                printf("%c\n",key[Get_next(root)]);
            }
            else if(c[] == 'M'){
                int x;
                scanf("%d",&x);
                splay(Get_kth(root,x+),);
                //debug();
            }
            else if(c[] == 'P'){
                splay(Get_pre(root),);
                //debug();
            }
            else {
                splay(Get_next(root),);
                //debug();
            }
        }
    }
}