Submission #673856

#	Time	Username	Problem	Language	Result	Execution time	Memory
673856		Dan4Life	Circle selection (APIO18_circle_selection)	C++17	7 / 100	3090 ms	33428 KiB

circle_selection

#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define int long long 
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) a.begin(),a.end()
using ll = long long;
const int maxn = (int)3e5+10;
const ll LINF = (ll)2e18;
struct circle{
	int x, y, r, i;
};

int n, elim[maxn];
vector<circle> v;

bool intersects(int i, int j){
	int rr = v[i].r+v[j].r;
	int xx = v[i].x-v[j].x;
	int yy = v[i].y-v[j].y;
	return rr*rr>=xx*xx+yy*yy;
}

int32_t main(){
	ios::sync_with_stdio(false); cin.tie(0); bool ok=true;
	cin >> n; v.resize(n); set<pair<int,int>> S;
	for(int i = 0; i < n; i++){
		cin >> v[i].x >> v[i].y >> v[i].r;
		v[i].i=i; elim[i]=-1; S.insert({v[i].x, i}); ok&=(v[i].y==0);
	}
	sort(all(v), [&](circle &a, circle &b){
		if(a.r!=b.r) return a.r > b.r;
		return a.i < b.i;
	});
	for(int i = 0; i < n; i++){
		if(elim[v[i].i]!=-1) continue;
		if(!ok){
			for(int j = i; j < n; j++)
				if(intersects(i,j) and elim[v[j].i]==-1) elim[v[j].i]=v[i].i;
		}
		else{
			while(!S.empty()){
				auto itr = S.lower_bound({v[i].x-v[i].r,-1});
				if(itr!=S.end() and itr->fi <= v[i].x) 
					elim[itr->se]=v[i].i, S.erase(itr);
				else break;
			}
		}
	}
	for(int i = 0; i < n; i++) cout << ++elim[i] << " ";
}
/*
11
9 9 2
13 2 1
11 8 2
3 3 2
3 12 1
12 14 1
9 8 5
2 8 2
5 2 1
14 4 2
14 14 1
*/

• Subtask 1: 7 / 7
• Subtask 2: 0 / 12
• Subtask 3: 0 / 15
• Subtask 4: 0 / 23
• Subtask 5: 0 / 30
• Subtask 6: 0 / 13