QOJ.ac
QOJ
ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#357608 | #2433. Panda Preserve | Crysfly | AC ✓ | 1267ms | 4800kb | C++17 | 7.5kb | 2024-03-19 02:22:01 | 2024-03-19 02:22:01 |
Judging History
answer
// what is matter? never mind.
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,sse4,popcnt,abm,mmx,avx,avx2")
#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
#define ll long long
//#define int long long
#define ull unsigned long long
#define SZ(x) ((int)((x).size()))
#define ALL(x) (x).begin(),(x).end()
using namespace std;
inline int read()
{
char c=getchar();int x=0;bool f=0;
for(;!isdigit(c);c=getchar())f^=!(c^45);
for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
if(f)x=-x;return x;
}
#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;
typedef double db;
const db eps=1e-10,pi=3.14159265358979323846;
int sgn(db x){return x<-eps?-1:x>eps;}
int cmp(db a,db b){return sgn(a-b);}
struct P{
db x,y;
P(db x=0,db y=0):x(x),y(y){}
P&operator +=(P o){return x+=o.x,y+=o.y,*this;}
P&operator -=(P o){return x-=o.x,y-=o.y,*this;}
P&operator *=(db o){return x*=o,y*=o,*this;}
P&operator /=(db o){return x/=o,y/=o,*this;}
friend P operator +(P a,P b){return a+=b;}
friend P operator -(P a,P b){return a-=b;}
friend P operator *(P a,db b){return a*=b;}
friend P operator /(P a,db b){return a/=b;}
friend bool operator <(P a,P b){return fabs(a.x-b.x)<eps?a.y<b.y:a.x<b.x;}
friend bool operator ==(P a,P b){return cmp(a.x,b.x)==0 && cmp(a.y,b.y)==0;}
friend db operator %(P a,P b){return a.x*b.x+a.y*b.y;} // dot
friend db operator *(P a,P b){return a.x*b.y-a.y*b.x;} // cross
P rot(db o){
db s=sin(o),c=cos(o),xx=x*c-y*s,yy=x*s+y*c;
x=xx,y=yy;return *this;
}
P rot90(){swap(x,y),x=-x;return *this;}
db ang(){return atan2(y,x);}
db l(){return sqrt(x*x+y*y);}
db l2(){return x*x+y*y;}
int half(){return sgn(y)==1||(sgn(y)==0&&sgn(x)>=0);}
P unit(){return ((*this))/l();}
void read(){cin>>x>>y;}
void out(){cout<<"("<<x<<","<<y<<")"<<endl;}
};
bool cmp_dir(P a,P b){
if(a.half()!=b.half())return a.half()<b.half();
return sgn(a*b)>0;
}
db dis(P a,P b){return (a-b).l();}
db cross(P a,P b,P c){
// (a->b)*(a->c)
return (b.x-a.x)*(c.y-a.y)-(b.y-a.y)*(c.x-a.x);
}
int cmp3(P a,P b,P c){
return sgn(cross(a,b,c));
}
bool paral(P p1,P p2,P q1,P q2){
// is parallel
return sgn((p2-p1)*(q2-q1))==0;
}
P interl(P p1,P p2,P q1,P q2){
// intersect point
db s1=cross(q1,q2,p1),s2=-cross(q1,q2,p2);
return (p1*s2+p2*s1)/(s1+s2);
}
bool inter(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);
}
bool ismid(db a,db m,db b){
return sgn(a-m)==0||sgn(b-m)==0||((a<m)!=(b<m));
}
bool ismid(P a,P m,P b){
return ismid(a.x,m.x,b.x)&&ismid(a.y,m.y,b.y);
}
bool chkseg(P p1,P p2,P q1,P q2){
return inter(p1.x,p2.x,q1.x,q2.x) && inter(p1.y,p2.y,q1.y,q2.y) &&
cmp3(p1,p2,q1)*cmp3(p1,p2,q2)<=0 && cmp3(q1,q2,p1)*cmp3(q1,q2,p2)<=0;
}
bool chkseg_strict(P p1,P p2,P q1,P q2){
return cmp3(p1,p2,q1)*cmp3(p1,p2,q2)<0 && cmp3(q1,q2,p1)*cmp3(q1,q2,p2)<0;
}
struct L{
P a,b;
L(P aa,P bb){a=aa,b=bb;}
bool in(P p){return sgn((b-a)*(p-a))>0;}
int in_sgn(P p){return sgn((b-a)*(p-a));}
P dir(){return b-a;}
bool onl(P p){
return cmp3(a,b,p)==0;
}
bool onseg(P p){
return onl(p)&&ismid(a,p,b);
}
bool onseg_strict(P p){
return onl(p)&&sgn((p-a)%(a-b))*sgn((p-b)%(a-b))<0;
}
void out(){cout<<"("<<a.x<<","<<a.y<<")---("<<b.x<<","<<b.y<<")\n";}
};
bool chkseg(L a,L b){
return chkseg(a.a,a.b,b.a,b.b);
}
bool paral(L a,L b){
// is parallel
return paral(a.a,a.b,b.a,b.b);
}
P operator &(L a,L b){
return interl(a.a,a.b,b.a,b.b);
}
bool samedir(L a,L b){
return paral(a,b) && sgn(a.dir()%b.dir())==1;
}
bool operator <(L a,L b){
if(samedir(a,b)) return b.in(a.a);
return cmp_dir(a.dir(),b.dir());
}
P proj(L a,P b){
P d=a.dir();
return a.a+d*((d%(b-a.a))/d.l2());
}
P reflect(L a,P b){
return proj(a,b)*2-b;
}
db rad(P a,P b){
return atan2l(a*b,a%b);
}
// polygon
db area(vector<P>a){
db res=0;
For(i,0,(int)a.size()-1)res+=a[i]*a[(i+1)%a.size()];
return res/2;
}
int contain(vector<P>a,P p){
int n=a.size(),res=0;
For(i,0,n-1){
P u=a[i],v=a[(i+1)%n];
if(L(u,v).onseg(p))return 1;
if(cmp(u.y,v.y)<=0)swap(u,v);
if(cmp(p.y,u.y)>0 || cmp(p.y,v.y)<=0)continue;
res^=cmp3(p,u,v)>0;
}
return res*2;
}
vector<P>cut(vector<P>a,P q1,P q2){
vector<P>b; int n=a.size();
For(i,0,n-1){
P p1=a[i],p2=a[(i+1)%n];
int d1=cmp3(q1,q2,p1),d2=cmp3(q1,q2,p2);
if(d1>=0)b.pb(p1);
if(d1*d2<0)b.pb(interl(p1,p2,q1,q2));
}
return b;
}
vector<P>convex(vector<P>a){
int n=a.size(),m=0; if(n<=1)return a;
sort(a.begin(),a.end());
vector<P>st(n*2); int tp=0;
For(i,0,n-1){
while(tp>1 && cmp3(st[tp-2],st[tp-1],a[i])<=0)--tp;
st[tp++]=a[i];
}
int t=tp;
Rep(i,n-2,0){
while(tp>t && cmp3(st[tp-2],st[tp-1],a[i])<=0)--tp;
st[tp++]=a[i];
}
st.resize(tp-1);
return st;
}
db diam(vector<P>a){
int n=a.size();
if(n<=1)return 0;
int ii=0,jj=0;
For(k,1,n-1){
if(a[k]<a[ii])ii=k;
if(a[jj]<a[k])jj=k;
}
int i=ii,j=jj;
db res=dis(a[i],a[j]);
do{
if((a[(i+1)%n]-a[i])*(a[(j+1)%n]-a[j])>=0) (++j)%=n;
else (++i)%=n;
res=max(res,dis(a[i],a[j]));
}while(i!=ii||j!=jj);
return res;
}
bool check(L a,L b,L c){
return c.in(a&b);
}
int checksgn(L a,L b,L c){
return c.in_sgn(a&b);
}
vector<P>hpis(vector<L>&l){
sort(l.begin(),l.end());
deque<L>q;
For(i,0,(int)l.size()-1){
if(i&&samedir(l[i],l[i-1]))continue;
while(q.size()>1 && !check(q[q.size()-2],q[q.size()-1],l[i]))q.pop_back();
while(q.size()>1 && !check(q[1],q[0],l[i]))q.pop_front();
q.pb(l[i]);
}
while(q.size()>2 && !check(q[q.size()-2],q[q.size()-1],q[0]))q.pop_back();
while(q.size()>2 && !check(q[1],q[0],q[q.size()-1]))q.pop_front();
vector<P>res;
For(i,0,(int)q.size()-1) res.pb(q[i]&q[(i+1)%q.size()]);
return res;
}
mt19937_64 rnd(64);
vector<L>cut(vector<L>a,L l){
vector<L>b; int n=a.size();
For(i,0,n-1){
L a1=a[i],a2=a[(i+1)%n],a3=a[(i+2)%n];
int d1=checksgn(a1,a2,l),d2=checksgn(a2,a3,l);
if(d1>0 || d2>0 || (d1==0&&d2==0)) b.pb(a2);
if(d1>=0 && d2<0) b.pb(l);
}
return b;
}
L bisector(P a,P b){
// contain a
P o=(a+b)*0.5;
// L res=L(o,o+((b-a).rot90())); assert(res.in(a));
return L(o,o+((b-a).rot90()));
}
vector<vector<L>> voronoi(vector<P>a){
int n=a.size();
vector<P>b=a;
shuffle(b.begin(),b.end(),rnd);
const db U=1e5;
vector<vector<L>> res(n,{
L(P(-U,-U),P(U,-U)),
L(P(U,-U),P(U,U)),
L(P(U,U),P(-U,U)),
L(P(-U,U),P(-U,-U))
});
For(i,0,n-1){
for(auto x:b){
if(dis(x,a[i])>eps) res[i]=cut(res[i],bisector(a[i],x));
}
// for(auto t:res[i]) t.out(); puts("---------");
}
return res;
}
#define maxn 400005
#define inf 0x3f3f3f3f
int n;
vector<P>a;
signed main()
{
n=read();
a.resize(n);
For(i,0,n-1)a[i].read();
auto vd=voronoi(a);
db res=0;
For(i,0,n-1){
auto v=vd[i];
int m=v.size();
vector<P>b(m);
For(j,0,m-1) b[j]=(v[j]&v[(j+1)%m]);
// For(j,0,m-1) b[j].out(); puts(";;b;;");
for(auto x:b) if(contain(a,x)) res=max(res,dis(x,a[i]));//cout<<"chkmax "<<dis(x,a[i])<<" "<<x.x<<" "<<x.y<<" "<<a[i].x<<" "<<a[i].y<<" "<<contain(a,x)<<"\n";
For(j,0,m-1) {
L x=L(b[j],b[(j+1)%m]);
For(k,0,n-1){
L y=L(a[k],a[(k+1)%n]);
if(!paral(x,y) && chkseg(x,y)){
P z=(x&y);
res=max(res,dis(z,a[i]));
}
}
}
}
printf("%.10lf\n",res);
return 0;
}
/*
*/
詳細信息
Test #1:
score: 100
Accepted
time: 1ms
memory: 4024kb
Test #2:
score: 0
Accepted
time: 0ms
memory: 3908kb
Test #3:
score: 0
Accepted
time: 0ms
memory: 3804kb
Test #4:
score: 0
Accepted
time: 0ms
memory: 3812kb
Test #5:
score: 0
Accepted
time: 1ms
memory: 3968kb
Test #6:
score: 0
Accepted
time: 1ms
memory: 3924kb
Test #7:
score: 0
Accepted
time: 1ms
memory: 4108kb
Test #8:
score: 0
Accepted
time: 0ms
memory: 3984kb
Test #9:
score: 0
Accepted
time: 0ms
memory: 4108kb
Test #10:
score: 0
Accepted
time: 0ms
memory: 3916kb
Test #11:
score: 0
Accepted
time: 0ms
memory: 4108kb
Test #12:
score: 0
Accepted
time: 0ms
memory: 3920kb
Test #13:
score: 0
Accepted
time: 1ms
memory: 3816kb
Test #14:
score: 0
Accepted
time: 0ms
memory: 3816kb
Test #15:
score: 0
Accepted
time: 0ms
memory: 3812kb
Test #16:
score: 0
Accepted
time: 0ms
memory: 3924kb
Test #17:
score: 0
Accepted
time: 1ms
memory: 3812kb
Test #18:
score: 0
Accepted
time: 0ms
memory: 3812kb
Test #19:
score: 0
Accepted
time: 0ms
memory: 3964kb
Test #20:
score: 0
Accepted
time: 0ms
memory: 4092kb
Test #21:
score: 0
Accepted
time: 0ms
memory: 3816kb
Test #22:
score: 0
Accepted
time: 1ms
memory: 3824kb
Test #23:
score: 0
Accepted
time: 1ms
memory: 3760kb
Test #24:
score: 0
Accepted
time: 1ms
memory: 4104kb
Test #25:
score: 0
Accepted
time: 1ms
memory: 3820kb
Test #26:
score: 0
Accepted
time: 0ms
memory: 3804kb
Test #27:
score: 0
Accepted
time: 0ms
memory: 3920kb
Test #28:
score: 0
Accepted
time: 0ms
memory: 3816kb
Test #29:
score: 0
Accepted
time: 0ms
memory: 3996kb
Test #30:
score: 0
Accepted
time: 0ms
memory: 3888kb
Test #31:
score: 0
Accepted
time: 1ms
memory: 3932kb
Test #32:
score: 0
Accepted
time: 1ms
memory: 3992kb
Test #33:
score: 0
Accepted
time: 0ms
memory: 4100kb
Test #34:
score: 0
Accepted
time: 0ms
memory: 3928kb
Test #35:
score: 0
Accepted
time: 1ms
memory: 4044kb
Test #36:
score: 0
Accepted
time: 1ms
memory: 4108kb
Test #37:
score: 0
Accepted
time: 1ms
memory: 3924kb
Test #38:
score: 0
Accepted
time: 0ms
memory: 3992kb
Test #39:
score: 0
Accepted
time: 0ms
memory: 3812kb
Test #40:
score: 0
Accepted
time: 1ms
memory: 4108kb
Test #41:
score: 0
Accepted
time: 1ms
memory: 3928kb
Test #42:
score: 0
Accepted
time: 0ms
memory: 3892kb
Test #43:
score: 0
Accepted
time: 0ms
memory: 3972kb
Test #44:
score: 0
Accepted
time: 1ms
memory: 4028kb
Test #45:
score: 0
Accepted
time: 1ms
memory: 4104kb
Test #46:
score: 0
Accepted
time: 1ms
memory: 4096kb
Test #47:
score: 0
Accepted
time: 0ms
memory: 3804kb
Test #48:
score: 0
Accepted
time: 0ms
memory: 3924kb
Test #49:
score: 0
Accepted
time: 0ms
memory: 3816kb
Test #50:
score: 0
Accepted
time: 1ms
memory: 3764kb
Test #51:
score: 0
Accepted
time: 1ms
memory: 3824kb
Test #52:
score: 0
Accepted
time: 3ms
memory: 3952kb
Test #53:
score: 0
Accepted
time: 50ms
memory: 4188kb
Test #54:
score: 0
Accepted
time: 194ms
memory: 4324kb
Test #55:
score: 0
Accepted
time: 3ms
memory: 3860kb
Test #56:
score: 0
Accepted
time: 66ms
memory: 3940kb
Test #57:
score: 0
Accepted
time: 265ms
memory: 4172kb
Test #58:
score: 0
Accepted
time: 3ms
memory: 3960kb
Test #59:
score: 0
Accepted
time: 63ms
memory: 4144kb
Test #60:
score: 0
Accepted
time: 260ms
memory: 4172kb
Test #61:
score: 0
Accepted
time: 2ms
memory: 3844kb
Test #62:
score: 0
Accepted
time: 47ms
memory: 4076kb
Test #63:
score: 0
Accepted
time: 188ms
memory: 4396kb
Test #64:
score: 0
Accepted
time: 1ms
memory: 3976kb
Test #65:
score: 0
Accepted
time: 0ms
memory: 3812kb
Test #66:
score: 0
Accepted
time: 0ms
memory: 3812kb
Test #67:
score: 0
Accepted
time: 0ms
memory: 4096kb
Test #68:
score: 0
Accepted
time: 760ms
memory: 4612kb
Test #69:
score: 0
Accepted
time: 0ms
memory: 4096kb
Test #70:
score: 0
Accepted
time: 775ms
memory: 4452kb
Test #71:
score: 0
Accepted
time: 50ms
memory: 4068kb
Test #72:
score: 0
Accepted
time: 691ms
memory: 4548kb
Test #73:
score: 0
Accepted
time: 132ms
memory: 4260kb
Test #74:
score: 0
Accepted
time: 689ms
memory: 4456kb
Test #75:
score: 0
Accepted
time: 183ms
memory: 4176kb
Test #76:
score: 0
Accepted
time: 9ms
memory: 3948kb
Test #77:
score: 0
Accepted
time: 9ms
memory: 4016kb
Test #78:
score: 0
Accepted
time: 9ms
memory: 4156kb
Test #79:
score: 0
Accepted
time: 9ms
memory: 3864kb
Test #80:
score: 0
Accepted
time: 9ms
memory: 3824kb
Test #81:
score: 0
Accepted
time: 9ms
memory: 4084kb
Test #82:
score: 0
Accepted
time: 10ms
memory: 4052kb
Test #83:
score: 0
Accepted
time: 6ms
memory: 4048kb
Test #84:
score: 0
Accepted
time: 9ms
memory: 4052kb
Test #85:
score: 0
Accepted
time: 9ms
memory: 3872kb
Test #86:
score: 0
Accepted
time: 4ms
memory: 3976kb
Test #87:
score: 0
Accepted
time: 9ms
memory: 3876kb
Test #88:
score: 0
Accepted
time: 9ms
memory: 3856kb
Test #89:
score: 0
Accepted
time: 9ms
memory: 3996kb
Test #90:
score: 0
Accepted
time: 9ms
memory: 4080kb
Test #91:
score: 0
Accepted
time: 9ms
memory: 3980kb
Test #92:
score: 0
Accepted
time: 810ms
memory: 4312kb
Test #93:
score: 0
Accepted
time: 747ms
memory: 4352kb
Test #94:
score: 0
Accepted
time: 2ms
memory: 3960kb
Test #95:
score: 0
Accepted
time: 3ms
memory: 4136kb
Test #96:
score: 0
Accepted
time: 8ms
memory: 3872kb
Test #97:
score: 0
Accepted
time: 7ms
memory: 3880kb
Test #98:
score: 0
Accepted
time: 1240ms
memory: 4792kb
Test #99:
score: 0
Accepted
time: 1267ms
memory: 4692kb
Test #100:
score: 0
Accepted
time: 1256ms
memory: 4508kb
Test #101:
score: 0
Accepted
time: 1259ms
memory: 4800kb
Test #102:
score: 0
Accepted
time: 1226ms
memory: 4612kb
Test #103:
score: 0
Accepted
time: 968ms
memory: 4492kb
Test #104:
score: 0
Accepted
time: 1191ms
memory: 4688kb