Submission #493206

#	Time	Username	Problem	Language	Result	Execution time	Memory
493206		inksamurai	Crtanje (COCI20_crtanje)	C++17	0 / 50	12 ms	312 KiB

crtanje

#include <bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) a.begin(),a.end()
#define rep(i,n) for(int i=0;i<n;i++)
#define crep(i,x,n) for(int i=x;i<n;i++)
#define drep(i,n) for(int i=n-1;i>=0;i--)
#define vec(...) vector<__VA_ARGS__>
#define _3cSpNGp ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0)
using namespace std;
typedef long long ll;
typedef long double ld;
using pii=pair<int,int>;
using vi=vector<int>;

struct dsu{
	int n,size_;
	vector<int> par,siz,color;
	dsu(int m){
		init(m);
	}
	void init(int m){
		n=m; size_=m;
		par.resize(n,0);siz.resize(n,0);color.resize(n,0);
		for(int i=0;i<n;i++){
			par[i]=i; siz[i]=1;
		}
	}
	void merge(int x,int y,int type=0){
		int a=parent(x),b=parent(y);
		if(a==b) return;
		size_--;
		if(siz[a]>siz[b]) {
			siz[a]+=siz[b];
			par[b]=a;
		}else{
			siz[b]+=siz[a];
			par[a]=b;
		}
	}
	int parent(int x){
		return par[x]==x?x:parent(par[x]);
	}
	bool same(int x, int y){
		return parent(x)==parent(y);
	}
	int size(){
		return size_;
	}
};

ld qu(ld d){
	return d*d;
}

int main(){
_3cSpNGp;
	int n;
	cin>>n;
	vec(pii) a(n);
	rep(i,n){
		cin>>a[i].fi>>a[i].se;
	}
	auto f=[&](ld rad)->bool{
		dsu uf(n);
		rep(i,n){
			crep(j,i+1,n){
				ld dist=qu(a[i].fi-a[j].fi)+qu(a[i].se-a[j].se);
				if(dist<=qu(2*rad)){
					uf.merge(i,j);
				}
			}
		}
		return uf.size()==1;
	};
	// cout<<f(1.5)<<"\n";
	ld l=0,r=1e9,c=-1;
	rep(_,300){
		ld m=(l+r)/2;
		if(f(m)){
			c=m;
			r=m;
		}else{
			l=m;
		}
	}
	cout<<fixed<<setprecision(8);
	cout<<c<<"\n";
//	
	return 0;
}

• Subtask 1: 0 / 50