Submission #302117

#	Time	Username	Problem	Language	Result	Execution time	Memory
302117		JPN20	Detecting Molecules (IOI16_molecules)	C++17	100 / 100	65 ms	6648 KiB

molecules

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

long long N;
pair<long long, int> W[1 << 18];
long long L, R;

vector<int> solve(int pos) {
	long long sum = 0;
	long long idx = -1;
	for (int i = 0; i < pos; i++) sum += W[i].first;
	if (L <= sum && sum <= R) {
		idx = 0;
	}
	else {
		for (int i = 1; i <= pos; i++) {
			sum -= W[pos - i].first;
			sum += W[N - i].first;
			if (L <= sum && sum <= R) { idx = i; break; }
		}
	}
	
	if (idx == -1) return vector<int> {};
	
	vector<int> vec;
	for (int i = 0; i < pos - idx; i++) vec.push_back(W[i].second);
	for (int i = 0; i < idx; i++) vec.push_back(W[N - 1 - i].second);
	sort(vec.begin(), vec.end());
	return vec;
}

vector<int> find_subset(int l, int u, vector<int> w) {
	N = w.size();
	L = l;
	R = u;
	for (int i = 0; i < N; i++) W[i] = make_pair(w[i], i);
	sort(W, W + N);
	
	// CALC1
	long long val = 0, cnt = -1;
	for (int i = 0; i < N; i++) {
		val += W[i].first;
		if (val >= l) { cnt = i + 1; break; }
	}
	if (cnt == -1) return vector<int>{};
	
	// CALC2
	vector<int> V1 = solve(cnt - 1);
	vector<int> V2 = solve(cnt);
	if (V1.size() >= 1) return V1;
	if (V2.size() >= 1) return V2;
	return vector<int>{};
}

• Subtask 1: 9 / 9
• Subtask 2: 10 / 10
• Subtask 3: 12 / 12
• Subtask 4: 15 / 15
• Subtask 5: 23 / 23
• Subtask 6: 31 / 31