LCT模板

之前一直用的LCT模板，因为其实个人对LCT和Splay不是很熟，所以用起来总觉得略略的坑爹，过了一段时间就忘了，但事实上很多裸的LCT要改的东西是不多的，所以今天写了些注释，以后可能套起模板来会得心应手一点吧－ －0

#pragma warning(disable:4996)
#include <iostream>
#include <cstring>
#include <string>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <map>
using namespace std;

#define ll long long
#define maxn 200000
#define INF 0x3f3f3f3f
#define INP INF+1
#define MP make_pair

void merge(int mxx[2], int nxx[2], int pval, int pnum)
{
    if (pval>mxx[0]){
        mxx[1] = mxx[0]; nxx[1] = nxx[0];
        mxx[0] = pval; nxx[0] = pnum;
    }
    else if (pval == mxx[0]){
        nxx[0] += pnum;
    }
    else if (pval>mxx[1]){
        mxx[1] = pval; nxx[1] = pnum;
    }
    else if(pval==mxx[1]){
        nxx[1] += pnum;
    }
}

struct Node
{
    /* Splay items(need not to be modified)*/
    Node *p, *ch[2];
    /* end */

    /* LCT items(need not to be modified)*/
    bool isRoot;
    Node *fa;
    /* end */

    /* tags to add(rev should always exist)*/
    bool rev;
    int add, cov;
    /* end */

    /* data need to be maintained*/
    int val, size;
    int mx[2], num[2];
    /* end */

    /* default value for the sentinel null(all the TAG and DATA should be set correcly)*/
    Node(){
        /* DATA */
        val = 0; size=0;
        mx[0] = mx[1] = -INF;
        num[0] = num[1] = 0;
        /* TAG */
        rev = 0;add = 0; cov = INP;
    }
    /* end */

    /* Splay function(need not to be modified)*/
    void setc(Node *c, int d){
        ch[d] = c;
        c->p = this;
    }
    bool d(){
        return p->ch[1] == this;
    }
    /* end */

    /* update function(maintain for ALL the DATA)*/
    void upd(){
        size = ch[0]->size + ch[1]->size + 1;
        mx[0] = ch[0]->mx[0]; num[0] = ch[0]->num[0];
        mx[1] = ch[0]->mx[1]; num[1] = ch[0]->num[1];
        merge(mx, num, val, 1);
        merge(mx, num, ch[1]->mx[0], ch[1]->num[0]);
        merge(mx, num, ch[1]->mx[1], ch[1]->num[1]);
    }
    /* end */

    /* tags function(for ALL the TAG,write a function)*/
    void revIt(){
        rev ^= 1;
        swap(ch[0], ch[1]);
    }
    void addIt(int vx){
        add += vx;
        val += vx;
        if (mx[0] != -INF) mx[0] += vx;
        if (mx[1] != -INF) mx[1] += vx;
    }
    void setIt(int vx){
        add = 0;
        cov = vx;
        val = vx;
        mx[0] = vx; num[0] = size;
        mx[1] = -INF; num[1] = 0;
    }
    /* end */

    void relax();
    void setRoot(Node *f);
}Tnull, *null = &Tnull;

/* function setRoot(need not to be modified) */
void Node::setRoot(Node *f){
    fa = f;
    isRoot = true;
    p = null;
}

/* function relax(need to be rewrite for ALL the TAG) */
void Node::relax(){
    if (cov != INP){
        for (int i = 0; i<2; ++i){
            if (ch[i] != null) ch[i]->setIt(cov);
        }
        cov = INP;
    }
    if (add != 0){
        for (int i = 0; i < 2; i++){
            if (ch[i] != null) ch[i]->addIt(add);
        }
        add = 0;
    }
    if (rev){
        for (int i = 0; i < 2; i++){
            if (ch[i] != null) ch[i]->revIt();
        }
        rev = 0;
    }
}

/* memory part(add C=mem for every iteration)*/
Node mem[maxn], *C = mem;

/* function make(need to set the default value for ALL the TAG and DATA)*/
Node *make(int v){
    /* DATA */
    C->size=1;
    C->val = v;
    C->mx[0] = v; C->num[0] = 1;
    C->mx[1] = -INF; C->num[1] = 0;
    /* TAG */
    C->rev = 0; C->add = 0;
    C->cov = INP;
    /* Pointer(need not to be modified) */
    C->ch[0] = C->ch[1] = null; C->isRoot = true;
    C->p = null;
    C->fa = null;
    return C++;
}

/* function rot(need not to be modified) */
void rot(Node *t){
    Node *p = t->p;
    p->relax();
    t->relax();
    bool d = t->d();
    p->p->setc(t, p->d());
    p->setc(t->ch[!d], d);
    t->setc(p, !d);
    p->upd();
    if (p->isRoot){
        p->isRoot = false;
        t->isRoot = true;
        t->fa = p->fa;
    }
}

/* function pushTo(need not to be modified) */
void pushTo(Node*t) {
    static Node*stk[maxn]; int top = 0;
    while (t != null) {
        stk[top++] = t;
        t = t->p;
    }
    for (int i = top - 1; i >= 0; --i) stk[i]->relax();
}

/* function splay(need not to be modified) */
void splay(Node*u, Node*f = null) {
    pushTo(u);
    while (u->p != f) {
        if (u->p->p == f)
            rot(u);
        else
            u->d() == u->p->d() ? (rot(u->p), rot(u)) : (rot(u), rot(u));
    }
    u->upd();
}

/* Node pointer array*/
Node *v[maxn];
/* The graph stored in the E*/
vector<int> E[maxn];
int n, nQ;

/* BFS items, using for construct the Tree */
int que[maxn], fa[maxn], qh = 0, qt = 0;
int wht[maxn];

/* function BFS(need not to be modified) */
void bfs()
{
    qh = qt = 0;
    que[qt++] = 1;
    fa[1] = -1;
    while (qh < qt){
        int u = que[qh++];
        for (int i = 0; i < E[u].size(); i++){
            int e = E[u][i];
            if (e != fa[u]){
                fa[e] = u;
                v[e]->fa = v[u];
                que[qt++] = e;
            }
        }
    }
}

/* function expose(need not to be modified) */
Node *expose(Node *u)
{
    Node *v;
    for (v = null; u != null; v = u, u = u->fa){
        splay(u);
        u->ch[1]->setRoot(u);
        u->setc(v, 1);
        v->fa = u;
    }
    return v;
}

/* function makeRoot(need not to be modified) */
void makeRoot(Node *u)
{
    expose(u);
    splay(u);
    u->revIt();
}

/* function addEdge(need not to be modified) */
void addEdge(Node *u, Node *v)
{
    makeRoot(v);
    v->fa = u;
}

/* function delEdge(need not to be modified) */
void delEdge(Node *u, Node *v)
{
    makeRoot(u);
    expose(v); splay(u); u->setc(null, 1); u->upd();
    v->setRoot(null);
}

/* function find root(need not to be modified) */
Node *find_root(Node *u)
{
    expose(u); splay(u);
    while (u->ch[0] != null){
        u = u->ch[0];
    }
    splay(u); return u;
}

/* function used for query*/
/***************************
prototype:
void xPath(Node *u,Node *v,(int ax))
{
    makeRoot(u);
    expose(v);
    splay(v);
    v->xIt((ax))
}
***************************/
void addPath(Node *u, Node *v, int ax)
{
    makeRoot(u);
    expose(v);
    splay(v);
    v->addIt(ax);
}

void setPath(Node *u, Node *v, int ax)
{
    makeRoot(u);
    expose(v);
    splay(v);
    v->setIt(ax);
}

pair<int, int> queryPath(Node *u, Node *v){
    makeRoot(u);
    expose(v);
    splay(v);
    return MP(v->mx[1], v->num[1]);
}

int main()
{
    int T; cin >> T;int ca=0;
    while (T--)
    {
        /*      Things to do     */
        /*************************
        C=mem;
        initialize E;
        read in the wht for nodes;
        make for each node;
        bfs();
        solve for query();
        **************************/
        C = mem;
        scanf("%d%d", &n, &nQ);
        for (int i = 1; i <= n; i++){
            scanf("%d", wht + i);
            v[i] = make(wht[i]);
        }
        for (int i = 0; i <= n; i++) E[i].clear();
        int ui, vi;
        for (int i = 0; i < n - 1; i++){
            scanf("%d%d", &ui, &vi);
            E[ui].push_back(vi); E[vi].push_back(ui);
        }
        bfs();
        int cmd, xi, yi, ai, bi;
        Node *nx, *ny, *na, *nb;
        printf("Case #%d:\n",++ca);
        while (nQ--){
            scanf("%d", &cmd);
            if (cmd == 1) scanf("%d%d%d%d", &xi, &yi, &ai, &bi);
            else if (cmd == 2 || cmd == 3) scanf("%d%d%d", &ai, &bi, &xi);
            else scanf("%d%d", &ai, &bi);

            if (cmd == 1){
                nx = v[xi]; ny = v[yi];
                na = v[ai]; nb = v[bi];
                delEdge(nx, ny);
                addEdge(na, nb);
            }
            else if (cmd == 2){
                nx = v[ai]; ny = v[bi];
                setPath(nx, ny, xi);
            }
            else if (cmd == 3){
                nx = v[ai]; ny = v[bi];
                addPath(nx, ny, xi);
            }
            else{
                nx = v[ai]; ny = v[bi];
                pair<int, int> ans = queryPath(nx, ny);
                if (ans.first <= -INF) printf("ALL SAME\n");
                else printf("%d %d\n", ans.first, ans.second);
            }
        }
    }
    return 0;
}