Submission #653372

#	Time	Username	Problem	Language	Result	Execution time	Memory
653372		Antekb	Balloons (CEOI11_bal)	C++14	70 / 100	2066 ms	65536 KiB

bal

#include<bits/stdc++.h>
 
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("trapv")
 
#define st first
#define nd second
#define pb push_back
#define pp pop_back
#define eb emplace_back
#define mp(a, b) make_pair(a, b)
#define all(x) (x).begin(), (x).end()
#define rev(x) reverse(all(x))
#define sor(x) sort(all(x))
#define sz(x) (int)(x).size()
#define rsz(x) resize(x)
 
using namespace std;
 
///~~~~~~~~~~~~~~~~~~~~~~~~~~
 
template <typename H, typename T> 
ostream& operator<<(ostream& os, pair<H, T> m){
	return os <<"("<< m.st<<", "<<m.nd<<")";
}
template <typename H> 
ostream& operator<<(ostream& os, vector<H> V){
	os<<"{";
	for(int i=0; i<V.size(); i++){
		if(i)os<<" ";
		os<<V[i];
	}
	os<<"}";
	return os;
}
 
void debug(){cerr<<"\n";}
template <typename H, typename... T>
void debug(H h, T... t) {cerr<<h; if (sizeof...(t)) cerr << ", "; debug(t...);}
#define deb(x...) cerr<<#x<<" = ";debug(x);
 
///~~~~~~~~~~~~~~~~~~~~~~~~~
 
typedef long long ll;
typedef double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<pii > vii;
typedef vector<ll> vl;
typedef vector<pll> vll;
typedef string str;
 
#define BOOST ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
 
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
 
const int N=2e5+5, mod=1e9+7;
const ld INF=1e9, EPS=1e-4;
struct line{
	ld a, b;
	line(ld a, ld b): a(a), b(b){}
	ld isect(line L){
		return (b-L.b)/(L.a-a);
	}
	ld val(ld x){return a*x+b;}
};
vi L, R;
vector<line> lines;
vector<int> li;
vector<ld> l, r;
vector<vector<pair<int, pair<ld, ld> > > > todo;
void insert(int v, int li2, ld l1, ld r1){
		//deb(l, r, li.a, li.b);
		//deb(l1, r1, li2.a, li2.b);
		if(r1<l1+EPS)return;
		if(lines[li2].val(l[v])>lines[li[v]].val(l[v])-EPS && lines[li2].val(r[v])>lines[li[v]].val(r[v])-EPS)return;
		//deb("a");
		if(l1==l[v] && r1==r[v] && lines[li2].val(l[v])<lines[li[v]].val(l[v]) && lines[li2].val(r[v])<lines[li[v]].val(r[v])){
			li[v]=li2;
			return;
		}
		ld m=(l[v]+r[v])/2;
		if(!L[v]){
			L[v]=L.size();
			L.pb(0), R.pb(0);
			l.pb(l[v]);
			r.pb(m);
			todo.pb({});
			li.pb(0);
			R[v]=L.size();
			L.pb(0), R.pb(0);
			r.pb(r[v]);
			l.pb(m);
			todo.pb({});
			li.pb(0);
		}
		if(l1<=m)todo[L[v]].pb({li2, {l1, min(r1, m)}});
		if(r1>=m)todo[R[v]].pb({li2, {max(l1, m), r1}});
		return;
}
ld val(int v, ld x){
		ld ans=lines[li[v]].val(x);
		if(todo[v].size()<5000){
			for(auto &i:todo[v]){
				if(x>=i.nd.st-EPS && x<=i.nd.nd+EPS)ans=min(ans, lines[i.st].val(x));
			}
		}
		else{
			for(auto &i:todo[v]){
				insert(v, i.st, i.nd.st, i.nd.nd);
			}
			todo[v].clear();
		}
		ans=min(ans, lines[li[v]].val(x));
		ld m=(l[v]+r[v])/2;
		if(x<m && L[v])ans=min(ans, val(L[v], x));
		else{
			if(R[v])ans=min(ans, val(R[v], x));
		}
		return ans;
}
/*struct node{
	node *L=nullptr, *R=nullptr;
	line li=line(0, INF);
	ld l=0, r=INF;
	node(ld l, ld r): l(l), r(r){}
	vector<pair<line, pair<ld, ld> > > todo;
	void insert(line li2, ld l1, ld r1){
		//deb(l, r, li.a, li.b);
		//deb(l1, r1, li2.a, li2.b);
		if(r1<l1+EPS)return;
		if(li2.val(l)>li.val(l)-EPS && li2.val(r)>li.val(r)-EPS)return;
		//deb("a");
		if(l1==l && r1==r && li2.val(l)<li.val(l) && li2.val(r)<li.val(r)){
			li=li2;
			return;
		}
		ld m=(l+r)/2;
		if(L==nullptr){
			L=new node(l, m);
			R=new node(m, r);
		}
		if(l1<=m)L->todo.pb({li2, {l1, min(r1, m)}});
		if(r1>=m)R->todo.pb({li2, {max(l1, m), r1}});
		return;
	}
	ld val(ld x){
		ld ans=li.val(x);
		if(todo.size()<500){
			for(auto &i:todo){
				if(x>=i.nd.st-EPS && x<=i.nd.nd+EPS)ans=min(ans, i.st.val(x));
			}
		}
		else{
			for(auto &i:todo){
				insert(i.st, i.nd.st, i.nd.nd);
			}
			todo.clear();
		}
		ans=min(ans, li.val(x));
		ld m=(l+r)/2;
		if(x<m && L)ans=min(ans, L->val(x));
		else{
			if(R)ans=min(ans, R->val(x));
		}
		return ans;
	}
};*/

int main(){
	//BOOST;
	int n;
	cin>>n;
	int root=0;
	L.pb(0), R.pb(0);
	l.pb(0);
	r.pb(INF);
	todo.pb({});
	li.pb(0);
	lines.pb(line(0, INF));
	for(int i=0; i<n; i++){
		int x, rr;
		cin>>x>>rr;
		ld r2=val(root, x);
		r2=min(r2*r2, ld(rr));
		cout<<fixed<<setprecision(3)<<r2<<"\n";
		if(r2>EPS){
			lines.pb(line(-1/ld(2*sqrt(r2)), x/ld(2*sqrt(r2))));
			insert(root, lines.size()-1, 0, x);
			lines.pb(line(1/ld(2*sqrt(r2)), -x/ld(2*sqrt(r2))));
			insert(root, lines.size()-1, x, INF);
		}
	}
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10