【动态树】 HDOJ 4010 Query on The Trees

都是动态树的基本操作。。。

#include <iostream>
#include <queue> 
#include <stack> 
#include <map> 
#include <set> 
#include <bitset> 
#include <cstdio> 
#include <algorithm> 
#include <cstring> 
#include <climits>
#include <cstdlib>
#include <cmath>
#include <time.h>
#define maxn 300005
#define maxm 600005
#define eps 1e-10
#define mod 1000000007
#define INF 0x3f3f3f3f
#define PI (acos(-1.0))
#define lowbit(x) (x&(-x))
#define mp make_pair
#define ls o<<1
#define rs o<<1 | 1
#define lson o<<1, L, mid 
#define rson o<<1 | 1, mid+1, R
#define pii pair<int, int>
//#pragma comment(linker, "/STACK:16777216")
typedef long long LL;
typedef unsigned long long ULL;
//typedef int LL;
using namespace std;
LL qpow(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base;base=base*base;b/=2;}return res;}
LL powmod(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base%mod;base=base*base%mod;b/=2;}return res;}
// head

struct node *null;
struct node
{
	int key, rise, Max, rev;
	node *fa, *ch[2];

	inline bool d()
	{
		return fa->ch[1] == this;
	}

	inline bool isroot()
	{
		return fa == null || fa->ch[0] != this && fa->ch[1] != this;
	}

	inline void setc(node *p, int d)
	{
		ch[d] = p;
		p->fa = this;
	}

	inline void flip()
	{
		if(this == null) return;
		swap(ch[0], ch[1]);
		rev ^= 1;
	}

	inline void add(int x)
	{
		if(this == null) return;
		key += x;
		Max += x;
		rise += x;
	}

	void pushup()
	{
		Max = max(key, max(ch[0]->Max, ch[1]->Max));
	}

	void pushdown()
	{
		if(rev) {
			ch[0]->flip();
			ch[1]->flip();
			rev = 0;
		}
		if(rise) {
			ch[0]->add(rise);
			ch[1]->add(rise);
			rise = 0;
		}
	}

	void rot()
	{
		node *f = fa, *ff = fa->fa;
		int c = d(), cc = fa->d();
		f->setc(ch[!c], c);
		this->setc(f, !c);
		if(ff->ch[cc] == f) ff->setc(this, cc);
		else this->fa = ff;
		f->pushup();
	}
	
	inline void go()
	{
		if(!isroot()) fa->go();
		pushdown();
	}

	node* splay()
	{
		go();
		while(!isroot()) {
			if(!fa->isroot()) d() == fa->d() ? fa->rot() : rot();
			rot();
		}
		pushup();
		return this;
	}

	node* access()
	{
		for(node *p = this, *q = null; p != null; q = p, p = p->fa) {
			p->splay()->setc(q, 1);
			p->pushup();
		}
		return splay();
	}

	node* findroot()
	{
		node *p;
		for(p = access(); p->ch[0] != null; p = p->ch[0]);
		return p;
	}

	void makeroot()
	{
		access()->flip();
	}

	void link(node *p)
	{
		if(findroot() == p->findroot()) printf("-1\n");
		else {
			makeroot();
			fa = p;
		}
	}

	void cut()
	{
		access();
		ch[0]->fa = null;
		ch[0] = null;
		pushup();
	}

	void cut(node *p)
	{
		if(p == this || findroot() != p->findroot()) printf("-1\n");
		else {
			p->makeroot();
			cut();
		}
	}
};

struct Edge
{
	int v;
	Edge *next;
}E[maxm], *H[maxn], *edges;

node *Node[maxn];
node pool[maxm];
queue<int> q;
node *tail;
int vis[maxn];
int n, m;

void addedges(int u, int v)
{
	edges->v = v;
	edges->next = H[u];
	H[u] = edges++;
}

void init()
{
	tail = pool;
	null = tail++;
	null->fa = null->ch[0] = null->ch[1] = null;
	null->key = null->rev = null->rise = null->Max = 0;
	edges = E;
	memset(H, 0, sizeof H);
	memset(vis, 0, sizeof vis);
}

void read()
{
	int u, v, x;
	for(int i = 1; i < n; i++) {
		scanf("%d%d", &u, &v);
		addedges(u, v);
		addedges(v, u);
	}
	for(int i = 1; i <= n; i++) {
		scanf("%d", &x);
		tail->key = tail->Max = x;
		tail->rev = tail->rise = 0;
		tail->fa = tail->ch[0] = tail->ch[1] = null;
		Node[i] = tail++;
	}
	scanf("%d", &m);
}

void bfs()
{
	vis[1] = 1;
	q.push(1);
	while(!q.empty()) {
		int u = q.front();
		q.pop();
		for(Edge *e = H[u]; e; e = e->next) {
			int v = e->v;
			if(vis[v]) continue;
			vis[v] = 1;
			q.push(v);
			Node[v]->fa = Node[u];
		}
	}
}

int query(node *a, node *b)
{
	a->access();
	for(a = null; b != null; a = b, b = b->fa) {
		b->splay();
		if(b->fa == null) return max(b->key, max(b->ch[1]->Max, a->Max));
		b->setc(a, 1);
		b->pushup();
	}
}

void update(node *a, node *b, int c)
{
	a->access();
	for(a = null; b != null; a = b, b = b->fa) {
		b->splay();
		if(b->fa == null) {
			if(a != null) a->add(c);
			if(b->ch[1] != null) b->ch[1]->add(c);
			b->key += c;
			b->Max += c;
			return;
		}
		b->setc(a, 1);
		b->pushup();
	}
}

void work()
{
	int k, a, b, c;
	bfs();
	while(m--) {
		scanf("%d", &k);
		if(k == 1) {
			scanf("%d%d", &a, &b);
			Node[a]->link(Node[b]);
		}
		if(k == 2) {
			scanf("%d%d", &a, &b);
			Node[b]->cut(Node[a]);
		}
		if(k == 3) {
			scanf("%d%d%d", &c, &a, &b);
			if(Node[a]->findroot() != Node[b]->findroot()) printf("-1\n");
			else update(Node[a], Node[b], c);
		}
		if(k == 4) {
			scanf("%d%d", &a, &b);
			if(Node[a]->findroot() != Node[b]->findroot()) printf("-1\n");
			else printf("%d\n", query(Node[a], Node[b]));
		}
	}
	printf("\n");
}

int main(void)
{
	while(scanf("%d", &n)!=EOF) {
		init();
		read();
		work();
	}
	
	
	return 0;
}