Submission #300683

#	Time	Username	Problem	Language	Result	Execution time	Memory
300683		JPN20	The Big Prize (IOI17_prize)	C++17	20 / 100	118 ms	3192 KiB

prize

#include "prize.h"
#include <bits/stdc++.h>
using namespace std;

int p1[1 << 18];
int p2[1 << 18];
int maxn = 0;
vector<int> V;
vector<int> W;

int Rand() {
	return (rand() % 32768) * 32768 + (rand() % 32768);
}

pair<int, int> query(int pos) {
	if (p1[pos] >= 0) return make_pair(p1[pos], p2[pos]);
	vector<int> vec = ask(pos);
	p1[pos] = vec[0];
	p2[pos] = vec[1];
	return make_pair(p1[pos], p2[pos]);
}

void dfs(int cl, int cr, int c1, int c2) {
	//cout << cl << " " << cr << " " << c1 << " " << c2 << endl;
	if (cl == cr) { W.push_back(V[cl]); return; }
	int cm = (cl + cr) / 2;
	int el = -1, e1 = 0;
	int er = -1, e2 = 0;
	for (int i = cm; i >= cl; i--) {
		pair<int, int> T = query(V[i]);
		if (T.first + T.second == maxn) { el = i; e1 = T.first; break; }
		else { W.push_back(V[i]); }
	}
	for (int i = cm; i <= cr; i++) {
		pair<int, int> T = query(V[i]);
		if (T.first + T.second == maxn) { er = i; e2 = T.first; break; }
		else { W.push_back(V[i]); }
	}
	if (el >= 0 && c1 != e1 && cl <= el + 1) dfs(cl, el - 1, c1, e1);
	if (er >= 0 && c2 != e2 && er + 1 <= cr) dfs(er + 1, cr, e2, c2);
}

vector<int> solve() {
	//for (int i = 0; i < V.size(); i++) cout << V[i] << " " ; cout << endl;
	maxn = 0; W.clear();
	for (int i = 0; i < 20; i++) {
		int T = Rand() % V.size();
		pair<int, int> T2 = query(V[T]);
		maxn = max(maxn, T2.first + T2.second);
	}
	//cout << maxn << endl;
	dfs(0, V.size() - 1, 0, maxn);
	return W;
}

int find_best(int n) {
	for (int i = 0; i < n; i++) p1[i] = -1;
	for (int i = 0; i < n; i++) p2[i] = -1;
	for (int i = 0; i < n; i++) V.push_back(i);
	while (V.size() >= 2) {
		vector<int> V2 = solve();
		sort(V2.begin(), V2.end());
		V2.erase(unique(V2.begin(), V2.end()), V2.end());
		V = V2;
	}
	return V[0];
}

• Subtask 1: 20 / 20
• Subtask 2: 0 / 80