https://www.cnblogs.com/ljh2000-jump/p/6423399.html

 1 #include<cmath>
 2 #include<vector>
 3 #include<cstdio>
 4 #include<algorithm>
 5 #define rep(i,l,r) for (int i=(l); i<=(r); i++)
 6 typedef long long ll;
 7 using namespace std;
 8 
 9 const int N=1200010;
10 int n,m,Q,x,y,d,cnt=1
 
,nxt[N],tot,rt,bel[N],fa[N],ask[N];
11 bool vis[N],in[N];
12 ll s[N],sp[N],fz,fm;
13 
14 struct P{ int x,y; }p[N];
15 P operator -(const P &a,const P &b){ return (P){a.x-b.x,a.y-b.y}; }
16 ll operator *(const P &a,const P &b){ return 1ll*a.x*b.y-1ll*b.x*a.y; }
17 
18 struct E{
 
19     int u,v,id; double sl;
20     E(){}; E(int a,int b,int i):u(a),v(b),id(i),sl(atan2(p[b].y-p[a].y,p[b].x-p[a].x)){}
21 }e[N];
22 bool operator <(const E &a,const E &b){ return a.sl<b.sl; }
23 vector<E>w[N],tr[N];
24 void add(int u,int v){ cnt++; e[cnt]=(E){u,v,cnt}; w[u].push_back(e[cnt]); }
 
25 
26 ll gcd(ll a,ll b){ return b ? gcd(b,a%b) : a; }
27 
28 int find(int x,E b){
29     int l=0,r=w[x].size()-1;
30     while (l<r){
31         int mid=(l+r+1)>>1;
32         if (b<w[x][mid]) r=mid-1; else l=mid;
33     }
34     return l;
35 }
36 
37 void dfs(int x){
38     vis[x]=1; sp[x]=s[x]*s[x]; s[x]<<=1; int ed=tr[x].size()-1;
39     rep(i,0,ed){
40         int v=tr[x][i].v; if (vis[v]) continue;
41         fa[v]=x; in[tr[x][i].id]=in[tr[x][i].id^1]=1;
42         dfs(v); s[x]+=s[v]; sp[x]+=sp[v];
43     }
44 }
45 
46 int main(){
47     freopen("bzoj4541.in","r",stdin);
48     freopen("bzoj4541.out","w",stdout);
49     scanf("%d%d%d",&n,&m,&Q);
50     rep(i,1,n) scanf("%d%d",&x,&y),p[i]=(P){x,y};
51     rep(i,1,m) scanf("%d%d",&x,&y),add(x,y),add(y,x);
52     rep(i,1,n) sort(w[i].begin(),w[i].end());
53     rep(i,2,cnt){
54         int ne=find(e[i].v,e[i^1])-1;
55         if (ne==-1) ne=w[e[i].v].size()-1;
56         nxt[i]=w[e[i].v][ne].id;
57     }
58     rep(i,2,cnt) if (!bel[i]){
59         bel[i]=bel[nxt[i]]=++tot;
60         for (int x=nxt[i]; e[x].v!=e[i].u; x=nxt[x],bel[x]=tot)
61             s[tot]+=(p[e[x].u]-p[e[i].u])*(p[e[x].v]-p[e[i].u]);
62         if (s[tot]<=0) rt=tot;
63     }
64     rep(i,2,cnt) tr[bel[i]].push_back(E(bel[i],bel[i^1],i));
65     dfs(rt);
66     while (Q--){
67         scanf("%d",&d); d=(d+fz)%n+1;
68         rep(i,1,d) scanf("%d",&ask[i]),ask[i]=(ask[i]+fz)%n+1;
69         ask[d+1]=ask[1]; fz=fm=0;
70         rep(i,1,d){
71             int x=w[ask[i]][find(ask[i],E(ask[i],ask[i+1],0))].id;
72             if (!in[x]) continue;
73             if (fa[bel[x]]==bel[x^1]) fm+=s[bel[x]],fz+=sp[bel[x]];
74                 else fm-=s[bel[x^1]],fz-=sp[bel[x^1]];
75         }
76         ll d=gcd(fz,fm); fz/=d; fm/=d; printf("%lld %lld\n",fz,fm);
77     }
78     return 0;
79 }

[BZOJ4541][HNOI2016]礦區(平面圖轉對偶圖)