loj2052 「HNOI2016」矿区

学习一发平面图的姿势……ref

#include <algorithm>
#include <iostream>
#include <cstdio>
#include <vector>
#include <cmath>
using namespace std;
typedef long long ll;
int n, m, k, cnt, uu, vv, nxt[1200005], bel[1200005], belcnt, rot, fa[1200005];
int ask[200005];
bool vis[1200005], isn[1200005];
ll s[1200005], sp[1200005];
struct Point{
	int x, y;
	Point operator-(const Point &u){
		return (Point){x-u.x, y-u.y};
	}
	ll operator*(const Point &u){
		return (ll)x*u.y-(ll)y*u.x;
	}
}p[200005];
struct Edge{
	int fro, too, idx;
	double ang;
	Edge(int f=0, int t=0, int i=0){
		fro = f; too = t; idx = i;
		ang = atan2(p[t].y-p[f].y, p[t].x-p[f].x);
	}
	bool operator<(const Edge &x)const{
		return ang<x.ang;
	}
}edge[1200005];
vector<Edge> w[200005], tr[1200005];
void add_edge(int fro, int too){
	edge[cnt] = Edge(fro, too, cnt);
	w[fro].push_back(edge[cnt]);
	cnt++;
}
ll getGcd(ll a, ll b){
	return !b?a:getGcd(b, a%b);
}
void rn(int &x){
	char ch=getchar();
	x = 0;
	int f=1;
	while(ch<'0' || ch>'9'){
		if(ch=='-')	f = -1;
		ch = getchar();
	}
	while(ch>='0' && ch<='9'){
		x = x * 10 + ch - '0';
		ch = getchar();
	}
	x *= f;
}
int findEdge(int f, const Edge &x){
	int l=0, r=w[f].size()-1, mid, re;
	while(l<=r){
		mid = (l + r) >> 1;
		if(w[f][mid]<x)	l = mid + 1;
		else	re = mid, r = mid - 1;
	}
	return re;
}
void dfs(int x){
	vis[x] = true;
	sp[x] = s[x] * s[x];
	s[x] <<= 1;
	for(int i=0; i<tr[x].size(); i++){
		int t=tr[x][i].too;
		if(vis[t])	continue;
		fa[t] = x;
		isn[tr[x][i].idx] = isn[tr[x][i].idx^1] = true;
		dfs(t);
		s[x] += s[t];
		sp[x] += sp[t];
	}
}
int main(){
	rn(n); rn(m); rn(k);
	for(int i=1; i<=n; i++){
		rn(p[i].x);
		rn(p[i].y);
	}
	for(int i=1; i<=m; i++){
		rn(uu); rn(vv);
		add_edge(uu, vv);
		add_edge(vv, uu);
	}
	for(int i=1; i<=n; i++)
		sort(w[i].begin(), w[i].end());
	for(int i=0; i<cnt; i++){
		int qwq=findEdge(edge[i].too, edge[i^1])-1;
		if(qwq==-1)	qwq = w[edge[i].too].size() - 1;
		nxt[i] = w[edge[i].too][qwq].idx;
	}
	for(int i=0; i<cnt; i++)
		if(!bel[i]){
			bel[i] = bel[nxt[i]] = ++belcnt;
			for(int j=nxt[i]; edge[j].too!=edge[i].fro; j=nxt[j]){
				s[belcnt] += (p[edge[j].fro]-p[edge[i].fro]) * (p[edge[j].too]-p[edge[i].fro]);
				bel[nxt[j]] = belcnt;
			}
			if(s[belcnt]<=0)	rot = belcnt;
		}
	for(int i=0; i<cnt; i++)
		tr[bel[i]].push_back(Edge(bel[i], bel[i^1], i));
	dfs(rot);
	ll p=0, q=0;
	int d;
	while(k--){
		rn(d); d = (d + p) % n + 1;
		for(int i=1; i<=d; i++){
			rn(ask[i]);
			ask[i] = (ask[i] + p) % n + 1;
		}
		ask[d+1] = ask[1];
		p = q = 0;
		for(int i=1; i<=d; i++){
			int j=w[ask[i]][findEdge(ask[i], Edge(ask[i],ask[i+1],0))].idx;
			if(!isn[j])	continue;
			if(fa[bel[j]]==bel[j^1])
				p += sp[bel[j]], q += s[bel[j]];
			else
				p -= sp[bel[j^1]], q -= s[bel[j^1]];
		}
		ll gcd=getGcd(p, q);
		p /= gcd; q /= gcd;
		printf("%lld %lld
", p, q);
	}
	return 0;
}