动态树 Link Cut Tree

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <vector>

using namespace std;

#define REP(i, a, b) for (int i = (a), _end_ = (b); i <= _end_; ++i)
#define DREP(i, a, b) for (int i = (a), _begin_ = (b); i >= _begin_; --i)
#define debug(...) fprintf(stderr, __VA_ARGS__)
#define mp make_pair
#define x first
#define y second
#define pb push_back
#define SZ(x) (int((x).size()))
#define ALL(x) (x).begin(), (x).end()

template<typename T> inline bool chkmin(T &a, const T &b){ return a > b ? a = b, 1 : 0; }
template<typename T> inline bool chkmax(T &a, const T &b){ return a < b ? a = b, 1 : 0; }

typedef long long LL;

const int dmax = 300100, oo = 0x3f3f3f3f;

int n, m;

struct node
{
    node *f, *ch[2];
    int val, max, rev, add;
}c[dmax], *cur, *Null;

#define L ch[0]
#define R ch[1]

node *new_node(int k)
{
    cur->val = cur->max = k;
    cur->rev = cur->add = 0;
    cur->f = cur->L = cur->R = Null;
    return cur++;
}

void init()
{
    Null = c;
    Null->f = Null->L = Null->R = Null;
    Null->val = Null->max = -oo;
    Null->rev = Null->add = 0;
    cur = c + 1;
}

struct lct
{
    inline bool is_root(node *t) { return t == Null || t->f->L != t && t->f->R != t; }
    inline void push_up(node *t) { t->max = max(t->val, max(t->L->max, t->R->max)); }
    inline void push_down(node *t)
    {
        if (t->rev)
        {
            if (t->L != Null) t->L->rev ^= 1;
            if (t->R != Null) t->R->rev ^= 1;
            t->rev = 0;
            swap(t->L, t->R);
        }
        if (t->add)
        {
            if (t->L != Null) t->L->val += t->add, t->L->max += t->add, t->L->add += t->add;
            if (t->R != Null) t->R->val += t->add, t->R->max += t->add, t->R->add += t->add;
            t->add = 0;
        }
    }
    inline void rotate(node *x)
    {
        if (is_root(x)) return;
        node *y = x->f;
        int k = x == y->R;
        x->f = y->f;
        y->ch[k] = x->ch[!k];
        if (x->ch[!k] != Null) x->ch[!k]->f = y;
        if (!is_root(y))
        {
            if (y == y->f->L)
                y->f->L = x;
            else y->f->R = x;
        }
        x->ch[!k] = y;
        y->f = x;
        push_up(y);
    }
    void splay(node *x)
    {
        static node *S[dmax];
        int top = 1;
        S[0] = x;
        for (node *Cur = x; !is_root(Cur); Cur = Cur->f)
            S[top++] = Cur->f;
        while (top > 0) push_down(S[--top]);
        while (!is_root(x))
        {
            node *y = x->f;
            if (!is_root(y))
                rotate(x);
            else{
                if (x == y->f->L->L || x == y->f->R->R)
                    rotate(y);
                else rotate(x);
                rotate(x);
            }
        }
        push_up(x);
    }
    node *access(node *x)
    {
        node *y = Null;
        while (x != Null)
        {
            splay(x);
            x->R = y;
            y->f = x;
            push_up(x);
            y = x;
            x = x->f;
        }
        return y;
    }
    inline void change_root(node *x) { access(x)->rev ^= 1; splay(x); }
    inline void link(node *x, node *y)
    {
        change_root(x);
        x->f = y;
        access(x);
    }
    inline void cut(node *x)
    {
        access(x);
        splay(x);
        x->L = x->L->f = Null;
        push_up(x);
    }
    node *get_root(node *x)
    {
        access(x);
        splay(x);
        while (x->L != Null) x = x->L;
        splay(x);
        return x;
    }
    bool p(node *x, node *y)
    {
        while (x->f != Null) x = x->f;
        while (y->f != Null) y = y->f;
        return x == y;
    }
}t;

int main()
{
    /* Do you want to do here */
    return 0;
}