【模板】Splay

如题，这是一个模板。。。

#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdio>
#include <cctype>

inline void read(int & x)
{
    x = 0;
    int k = 1;
    char c = getchar();
    while (!isdigit(c))
        if (c == '-') c = getchar(), k = -1;
        else c = getchar();
    while (isdigit(c))
        x = (x << 1) + (x << 3) + (c ^ 48),
        c = getchar();
    x *= k;
}

const int MAXN = 101010;

int rt = 0, tot = 0;
int faz[MAXN], siz[MAXN], cnt[MAXN], val[MAXN], son[MAXN][2];

int Getson(int u)
{
    return son[faz[u]][1] == u;
}

void Pushup(int u)
{
    siz[u] = siz[son[u][0]] + siz[son[u][1]] + cnt[u];
}

void Rotate(int u)
{
    int y = faz[u], z = faz[y], ch = Getson(u);
    int b = son[u][ch ^ 1], d = Getson(y);
    son[u][ch ^ 1] = y, son[y][ch] = b;
    faz[y] = u, faz[b] = y, faz[u] = z;
    if (z) son[z][d] = u;
    Pushup(y), Pushup(u);
}

void Splay(int u, int tar)
{
    while (faz[u] != tar)
    {
        if (faz[faz[u]] != tar)
            if (Getson(u) == Getson(faz[u])) Rotate(faz[u]);
            else Rotate(u);
        Rotate(u);
    }
    if (!tar) rt = u;
}

int Getmin(int u)
{
    while (son[u][0]) u = son[u][0];
    return u;
}

int Getmax(int u)
{
    while (son[u][1]) u = son[u][1];
    return u;
}

int Getx(int x)
{
    int cur = rt, las = 0;
    while (cur && val[cur] != x)
    {
        las = cur;
        if (x < val[cur]) cur = son[cur][0];
        else cur = son[cur][1];
    }
    return cur ? cur : las;
}

//void Insert(int x)
//{
//    int u = Getx(x);
//    if (u && val[u] == x)
//    {
//        ++cnt[u];
//        ++siz[u];
//        Splay(u, 0);
//        return;
//    }
//    val[++tot] = x;
//    faz[tot] = u;
//    cnt[tot] = siz[tot] = 1;
//    if (u) son[u][x > val[u]] = tot;
//    if (!rt) rt = tot;
//    Splay(tot, 0);
//}

inline void Insert(int x)
{
    int u = rt, las = 0;
    while (u)
    {
        las = u;
        if (x == val[u]) 
        {
            ++siz[u];
            ++cnt[u];
            Splay(u, 0); 
            return; 
        }
        if (x > val[u]) u = son[u][1];
        else u = son[u][0];
    }
    u = ++tot;
    val[u] = x;
    faz[u] = las;
    son[las][x > val[las]] = u;
    siz[u] = cnt[u] = 1;
    son[u][0] = son[u][1] = 0;
    if (!rt) rt = u;
    Splay(u, 0);
}

//void Delete(int x)
//{
//    int u = Getx(x);
//    Splay(u, 0);
//    if (cnt[u] > 1)  { --cnt[u], --siz[u]; return; }
//    if (!son[u][0] || !son[u][1]) { rt = son[u][0] | son[u][1]; faz[rt] = 0; return; }
//    faz[son[u][0]] = 0;
//    int bg = Getmax(son[u][0]);
//    Splay(bg, 0);
//    son[bg][1] = son[u][1];
//    faz[son[u][1]] = bg;
//}

inline void Delete(int x)
{
    int u = rt;
    while (u)
    {
        if (x == val[u]) 
        {
            Splay(u, 0);
            if (cnt[u] > 1)
            { --cnt[u], --siz[u]; return; }
            if (!son[u][0] || !son[u][1]) 
            { rt = son[u][0] | son[u][1]; faz[rt] = 0; return; }
            faz[son[u][0]] = faz[son[u][1]] = 0;
            int newrt = Getmin(son[u][1]);
            faz[son[u][0]] = newrt;
            son[newrt][0] = son[u][0];
            Splay(newrt, 0);
            Pushup(newrt);
            return;
        }
        else if (x > val[u]) u = son[u][1];
        else u = son[u][0];
    }
}

inline int GetKth(int k)
{
    int u = rt;
    while (u)
        if (siz[son[u][0]] >= k) u = son[u][0];
        else if (siz[son[u][0]] + cnt[u] < k) k -= siz[son[u][0]] + cnt[u], u = son[u][1];
        else return val[u];
}

int GetRank(int x)
{
    int u = Getx(x);
    Splay(u, 0);
    return siz[son[u][0]] + 1;
}

int Pre(int x)
{
    int u = Getx(x);
       if (val[u] < x) return val[u];
    return val[Getmax(son[u][0])];
}

int Suf(int x)
{
    int u = Getx(x);
       if (val[u] > x) return val[u];
    return val[Getmin(son[u][1])];
}

int n, m, opt, x;

signed main()
{
    read(m);
    for (int i = 1; i <= m; ++i)
    {
        read(opt), read(x);
        if (opt == 1) Insert(x);
        if (opt == 2) Delete(x);
        if (opt == 3) printf("%d\n", GetRank(x));
        if (opt == 4) printf("%d\n", GetKth(x));
        if (opt == 5) printf("%d\n", Pre(x));
        if (opt == 6) printf("%d\n", Suf(x));
    }
    return 0;
}