zoj2589
发布时间:2020-12-16 10:46:36 所属栏目:百科 来源:网络整理
导读:是cf933C的升级版。 平面图欧拉定理。over! f=e-v+c+1 c是联通块,相交才视为一块。 e是圆弧数,v是顶点数。 #include bits/stdc++.h#define pii pairint,int#define mp make_pair#define fi first#define se second#define pb push_backusing namespace st
是cf933C的升级版。 #include <bits/stdc++.h> #define pii pair<int,int> #define mp make_pair #define fi first #define se second #define pb push_back using namespace std; typedef double db; const db eps=1e-6; const db pi=acos(-1); int sign(db k){ if (k>eps) return 1; else if (k<-eps) return -1; return 0; } int cmp(db k1,db k2){return sign(k1-k2);} int inmid(db k1,db k2,db k3){return sign(k1-k3)*sign(k2-k3)<=0;}// k3 在 [k1,k2] 内 struct point{ db x,y; point operator + (const point &k1) const{return (point){k1.x+x,k1.y+y};} point operator - (const point &k1) const{return (point){x-k1.x,y-k1.y};} point operator * (db k1) const{return (point){x*k1,y*k1};} point operator / (db k1) const{return (point){x/k1,y/k1};} int operator == (const point &k1) const{return cmp(x,k1.x)==0&&cmp(y,k1.y)==0;} // 逆时针旋转 point turn(db k1){return (point){x*cos(k1)-y*sin(k1),x*sin(k1)+y*cos(k1)};} point turn90(){return (point){-y,x};} bool operator < (const point k1) const{ int a=cmp(x,k1.x); if (a==-1) return 1; else if (a==1) return 0; else return cmp(y,k1.y)==-1; } db abs(){return sqrt(x*x+y*y);} db abs2(){return x*x+y*y;} db dis(point k1){return ((*this)-k1).abs();} point unit(){db w=abs(); return (point){x/w,y/w};} void scan(){double k1,k2; scanf("%lf%lf",&k1,&k2); x=k1; y=k2;} void print(){printf("%.11lf %.11lfn",x,y);} db getw(){return atan2(y,x);} point getdel(){if (sign(x)==-1||(sign(x)==0&&sign(y)==-1)) return (*this)*(-1); else return (*this);} int getP() const{return sign(y)==1||(sign(y)==0&&sign(x)==-1);} }; int inmid(point k1,point k2,point k3){return inmid(k1.x,k2.x,k3.x)&&inmid(k1.y,k2.y,k3.y);} db cross(point k1,point k2){return k1.x*k2.y-k1.y*k2.x;} db dot(point k1,point k2){return k1.x*k2.x+k1.y*k2.y;} db rad(point k1,point k2){return atan2(cross(k1,k2),dot(k1,k2));} // -pi -> pi int compareangle (point k1,point k2){//极角排序+ return k1.getP()<k2.getP()||(k1.getP()==k2.getP()&&sign(cross(k1,k2))>0); } point proj(point k1,point q){ // q 到直线 k1,k2 的投影 point k=k2-k1;return k1+k*(dot(q-k1,k)/k.abs2()); } point reflect(point k1,point q){return proj(k1,k2,q)*2-q;} int clockwise(point k1,point k3){// k1 k2 k3 逆时针 1 顺时针 -1 否则 0 return sign(cross(k2-k1,k3-k1)); } int checkLL(point k1,point k3,point k4){// 求直线 (L) 线段 (S)k1,k2 和 k3,k4 的交点 return cmp(cross(k3-k1,k4-k1),cross(k3-k2,k4-k2))!=0; } point getLL(point k1,point k4){ db w1=cross(k1-k3,k4-k3),w2=cross(k4-k3,k2-k3); return (k1*w2+k2*w1)/(w1+w2); } int intersect(db l1,db r1,db l2,db r2){ if (l1>r1) swap(l1,r1); if (l2>r2) swap(l2,r2); return cmp(r1,l2)!=-1&&cmp(r2,l1)!=-1; } int checkSS(point k1,point k4){ return intersect(k1.x,k3.x,k4.x)&&intersect(k1.y,k3.y,k4.y)&& sign(cross(k3-k1,k4-k1))*sign(cross(k3-k2,k4-k2))<=0&& sign(cross(k1-k3,k2-k3))*sign(cross(k1-k4,k2-k4))<=0; } db disSP(point k1,point q){ point k3=proj(k1,q); if (inmid(k1,k3)) return q.dis(k3); else return min(q.dis(k1),q.dis(k2)); } db disSS(point k1,point k4){ if (checkSS(k1,k3,k4)) return 0; else return min(min(disSP(k1,k3),disSP(k1,k4)),min(disSP(k3,k4,k1),disSP(k3,k2))); } int onS(point k1,point q){return inmid(k1,q)&&sign(cross(k1-q,k2-k1))==0;} struct circle{ point o; db r; void scan(){o.scan(); scanf("%lf",&r);} int inside(point k){return cmp(r,o.dis(k));} }; int checkposCC(circle k1,circle k2){// 返回两个圆的公切线数量 if (cmp(k1.r,k2.r)==-1) swap(k1,k2); db dis=k1.o.dis(k2.o); int w1=cmp(dis,k1.r+k2.r),w2=cmp(dis,k1.r-k2.r); if (w1>0) return 4; else if (w1==0) return 3; else if (w2>0) return 2; else if (w2==0) return 1; else return 0; } vector<point> getCC(circle k1,circle k2){// 沿圆 k1 逆时针给出,相切给出两个 int pd=checkposCC(k1,k2); if (pd==0||pd==4) return {}; db a=(k2.o-k1.o).abs2(),cosA=(k1.r*k1.r+a-k2.r*k2.r)/(2*k1.r*sqrt(max(a,(db)0.0))); db b=k1.r*cosA,c=sqrt(max((db)0.0,k1.r*k1.r-b*b)); point k=(k2.o-k1.o).unit(),m=k1.o+k*b,del=k.turn90()*c; return {m-del,m+del}; } int t,n,vis[55]; circle c[55]; set<point> s; vector<point> v; set<pii> st; void slove(int x){ vis[x]=1; for(auto p:st){ for(int i=0;i<n;i++){ if(vis[p.fi]||vis[p.se]){ vis[p.fi]=vis[p.se]=1; break; } } } } int main(){ scanf("%d",&t); while (t--) { v.clear(); s.clear(); st.clear(); memset(vis,sizeof(vis)); scanf("%d",&n); for (int i = 0; i < n; i++) { scanf("%lf%lf%lf",&c[i].o.x,&c[i].o.y,&c[i].r); } int p = 0; for (int i = 0; i < n; i++) { for (int j = i + 1; j < n; j++) { v = getCC(c[i],c[j]); for (auto t:v)s.insert(t); if(!v.empty()) st.insert(pii(i,j)); } } for(int i=0;i<n;i++){ if(!vis[i]) { slove(i); p++; } } int e=0,v; v = s.size(); for (int i = 0; i < n; i++) { for (auto x:s) { if (c[i].inside(x) == 0) e++; } } cout << e - v + 1 + p << endl; } } (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |