Submission #317584

#	Time	Username	Problem	Language	Result	Execution time	Memory
317584		Kevin_Zhang_TW	Circle selection (APIO18_circle_selection)	C++17	100 / 100	1529 ms	48856 KiB

circle_selection

#include<bits/stdc++.h>
#define pb emplace_back
#define AI(i) begin(i), end(i)
using namespace std;
using ll = long long;
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void debug(auto L, auto R) { while (L < R) cerr << *L << " \n"[L+1==R], ++L; }
void kout(){ cerr << endl; }
template<class T1, class ...T2> void kout(T1 a, T2 ...e) { cerr << a << ' ', kout(e...); }
#else
#define DE(...) 0
#define debug(...) 0
#endif
const int MAX_N = 300010, MAX_K = 32;
int n;
ll up(ll v) { return v * v; }
int die[MAX_N];
struct cir {
	ll x, y, r, id;
	pair<int,int> div(int d) {
		return {x/d, y/d};
	}
	friend bool inter(cir a, cir b) {
		return up(a.x-b.x) + up(a.y-b.y) <= up(a.r+b.r);
	}
	bool operator < (cir a) {
		return make_pair(-r, id) < make_pair(-a.r, a.id);
	}
	bool set(cir killer) {
		if (die[id] != -1) 
			return true;
		if (inter(killer, *(this)))
			return die[id] = killer.id, true;
		return false;
	}
	bool dead() { return die[id] != -1; }
	friend istream& operator >> (istream& in, cir &a) {
		static int cnt;
		//const static ll dx = 12398291, dy = -23412845234;
		const static ll dx = 0, dy = 0;
		return a.id = cnt++, in >> a.x >> a.y >> a.r, a.x += dx, a.y += dy, in;
	}
}a[MAX_N];
void brute_force() {
	for (int i = 0;i < n;++i) {
		int id = a[i].id;
		if (~die[id]) continue;
		die[id] = id;
		for (int j = i+1;j < n;++j) 
			a[j].set(a[i]);
	}
}
//random_device rd;
//mt19937 gen(rd());
//uniform_int_
//struct hs {
//	size_t operator()(pair<int,int> a) const {
//		const static unsigned long long f = 9823419848328479ll;
//	   	return f * a.first - a.second + (a.first ^ a.second);
//	}
//};
//
//unordered_map<pair<int,int>, vector<int>, hs> mp[MAX_K];
struct allcir {
	vector<pair<int,vector<pair<int,int>>>> mp;
	ll block_size = 1ll << 31;
	void shrink(ll sz) {
		if (sz < block_size) 
			block_size = sz, putall();
	}
	void putall() {
		mp.clear();
		vector<pair< pair<int,int> , int > > allp;
		for (int i = 0;i < n;++i) if (!a[i].dead())
			allp.pb( a[i].div(block_size), i );
		sort(AI(allp));
		for (auto [P, id] : allp) {
			if (mp.empty() || P.first != mp.back().first)
				mp.pb(P.first, 0);
			mp.back().second.pb(P.second, id);
		}
		for (auto &[x, v] : mp)
			sort(AI(v));
	}
	void killall(cir a) {
		auto [x, y] = a.div(block_size);
		auto it = lower_bound(AI(mp), pair<int,vector<pair<int,int>>>{x-2, vector<pair<int,int>>{}});
		while (it != end(mp) && x + 2 >= it->first) {
			auto &vec = it->second;
			auto vit = lower_bound(AI(vec), pair<int,int>{ y - 2, -1});
			while (vit != end(vec) && y + 2 >= vit->first) 
				::a[vit->second].set(a), ++vit;
			++it;
		}
	}
}grid;
void solve_all() {
//	for (int i = 0;i < n;++i) {
//		for (int j = 0;j < MAX_K;++j) 
//			mp[j][ a[i].div(1ll<<j) ].pb(i);
//	}
	grid.putall();

	for (int i = 0;i < n;++i) {
		if (a[i].dead())
			continue;

		a[i].set(a[i]);

		int j = 0;
		while ((1ll<<j) < a[i].r)
			++j;

		grid.shrink(1ll << j);


		grid.killall(a[i]);
//		for (int r : {j}) {
//			grid.killall(a[i]);
//			auto &mp = ::mp[r];
//			auto [x, y] = a[i].div(1ll << r);
//			for (int nx : {x-2, x-1, x, x+1, x+2})
//				for (int ny : {y-2, y-1, y, y+1, y+2})
//					if (mp.count({nx, ny})) {
//						auto &V = mp[{nx, ny}];
//						vector<int> nv;
//						for (int j : V)
//							if (!a[j].set(a[i]))
//								nv.pb(j);
//						swap(nv, V);
//					}
//			break;
//		}
	}
}
//void testmap() {
//	mp.reserve(n * 10);
//	int rad = a[0].r ;
//	for (int i = 1;i < n;++i)
//		if (rad != a[i].r) exit(1);
//
//	rad <<= 1;
//
//	for (int i = 0;i < n;++i)
//		mp[ a[i].div(rad) ].pb(i);
//
//	for (int i = 0;i < n;++i) {
//		if (a[i].dead()) continue;
//		a[i].set(a[i]);
//		auto [x, y] = a[i].div(rad);
//
//		for (int nx : {x-1, x, x+1})
//			for (int ny : {y-1, y, y+1})
//				if (mp.count({nx, ny})) {
//					auto &V = mp[{nx, ny}];
//					vector<int> nv;
//					for (int j : V)
//						if (!a[j].set(a[i]))
//							nv.pb(j);
//					swap(nv, V);
//				}
//	}
//}
void solve() {
	sort(a, a+n);
	fill(die, die+n, -1);
	solve_all();
}
signed main(){
	ios_base::sync_with_stdio(0), cin.tie(0);
	cin >> n;
	for (int i = 0;i < n;++i)
		cin >> a[i];
	solve();
	for (int i = 0;i < n;++i)
		cout << die[i]+1 << " \n"[i+1==n];
}

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