【动态树】 HDOJ 5333 Undirected Graph

边和询问排序。。。。然后用LCT维护图。。。。

#include <bits/stdc++.h>
using namespace std;

#define lowbit(x) (x&(-x))
#define mp(x, y) make_pair(x, y)

const int maxn = 200005;
const int maxm = 500005;
const int INF = 0x3f3f3f3f;

struct node *null;
struct node
{
	int size, rev;
       	pair<int, int> Min, cMin;
	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 pushup()
	{
		size = ch[0]->size + ch[1]->size + 1;
		Min = cMin;
		if(ch[0] != null) Min = min(Min, ch[0]->Min);
		if(ch[1] != null) Min = min(Min, ch[1]->Min);
	}

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

	inline void go()
	{
		if(!isroot()) fa->go();
		pushdown();
	}

	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();
	}

	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();
	}

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

	node* getroot() {
		node *x;
		for(x = access(); x->pushdown(), x->ch[0] != null; x = x->ch[0]);
		return x;
	}

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

	void cut(node *o)
	{
		makeroot();
		o->cut();
	}

	void link(node *p)
	{
		makeroot();
		fa = p;
	}
};

struct qu
{
	int L, R, id;
	qu(int L = 0, int R = 0, int id = 0) : L(L), R(R), id(id) {}
}q[maxn];

node pool[maxm];
node *Node[maxn];
node *E[maxn];
int tree[maxn];
int res[maxn];
int f[maxn];
pair<int, int> e[maxn];
node *tail;
int n, m, m2;

int cmp(qu a, qu b)
{
	return a.R < b.R;
}

void init()
{
	memset(tree, 0, sizeof tree);
	tail = pool;
	null = tail++;
	null->fa = null->ch[0] = null->ch[1] = null;
	null->size = null->rev = 0, null->Min = null->cMin = mp(INF, INF);
	for(int i = 1; i <= n; i++) {
		tail->size = 1;
		tail->rev = 0;
		tail->ch[0] = tail->ch[1] = tail->fa = null;
		tail->Min = tail->cMin = mp(INF, INF);
		Node[i] = tail++;
	}
	for(int i = 1; i <= m; i++) {
		tail->size = 1;
		tail->rev = 0;
		tail->ch[0] = tail->ch[1] = tail->fa = null;
		tail->Min = tail->cMin = mp(INF, INF);
		E[i] = tail++;
	}
}

pair<int, 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 min(b->ch[1]->Min, a->Min);
		b->setc(a, 1);
		b->pushup();
	}
}

int find(int u)
{
	return f[u] = f[u] == u ? f[u] : find(f[u]);
}

void merge(int a, int b)
{
	int aa = f[a], bb = f[b];
	f[aa] = bb;
}

void add(int x, int v)
{
	for(int i = x; i > 0; i -= lowbit(i)) tree[i] += v;
}

int sum(int x)
{
	int res = 0;
	for(int i = x; i <= n; i += lowbit(i)) res += tree[i];
	return res;
}

void work()
{
	int u, v;
	for(int i = 1; i <= m; i++) {
		scanf("%d%d", &u, &v);
		if(u < v) swap(u, v);
		e[i] = mp(u, v);
	}
	
	sort(e+1, e+m+1);
	
	for(int i = 1; i <= m2; i++) {
		scanf("%d%d", &u, &v);
		if(u > v) swap(u, v);
		q[i] = qu(u, v, i);
	}
	sort(q+1, q+m2+1, cmp);
	
	for(int i = 1; i <= n; i++) f[i] = i;
	for(int i = 1, j = 1; j <= m2; j++) {
		while(i <= m && e[i].first <= q[j].R) {
			if(e[i].first == e[i].second) {
				i++;
				continue;
			}
			if(find(e[i].first) == find(e[i].second)) {
				pair<int, int> tpair = query(Node[e[i].first], Node[e[i].second]);
				int t = tpair.second;
				if(tpair.first <= e[i].second) {
					E[t]->cut(Node[e[t].first]);
					E[t]->cut(Node[e[t].second]);
					add(e[t].second, -1);
					
					E[i]->cMin = mp(e[i].second, i);
					E[i]->link(Node[e[i].first]);
					E[i]->link(Node[e[i].second]);
					add(e[i].second, 1);
				}
			}
			else {
				E[i]->cMin = mp(e[i].second, i);
				E[i]->link(Node[e[i].first]);
				E[i]->link(Node[e[i].second]);
				add(e[i].second, 1);
				merge(e[i].first, e[i].second);
			}
			i++;
		}
		res[q[j].id] = n - sum(q[j].L);
	}
	for(int i = 1; i <= m2; i++) printf("%d\n", res[i]);	
}

int main()
{
//	freopen("input", "r", stdin);
//	freopen("output", "w", stdout);
	while(scanf("%d%d%d", &n, &m, &m2) != EOF) {
		init();
		work();
	}
	
	return 0;
}