Submission #251713

#	Time	Username	Problem	Language	Result	Execution time	Memory
251713		tutis	Detecting Molecules (IOI16_molecules)	C++17	100 / 100	77 ms	7832 KiB

molecules

/*input
4 15 17
6 8 8 7
*/
#include "molecules.h"
#include <bits/stdc++.h>
using namespace std;
std::vector<int> find_subset(int l, int u, std::vector<int> w)
{
	int a = u - l;
	int n = w.size();
	vector<int>v(n);
	for (int i = 0; i < n; i++)
		v[i] = i;
	sort(v.begin(), v.end(), [&](int a, int b) {return w[a] < w[b];});
	long long w_mn = *min_element(w.begin(), w.end());
	vector<int>x(n);
	for (int i = 0; i < n; i++)
		x[i] = w[i] - w_mn;
	vector<long long>suma;
	suma.push_back(0);
	for (int i = 0; i < n; i++)
		suma.push_back(suma.back() + x[v[i]]);
	for (long long k = 1; k <= n; k++)
	{
		long long mini = w_mn * k + suma[k];
		long long maxi = w_mn * k + suma[n] - suma[n - k];
		if (mini < l && maxi < l)
			continue;
		if (mini > u && maxi > u)
			continue;
		if (u <= mini && mini <= l)
		{
			vector<int>ans;
			for (int i = 0; i < k; i++)
				ans.push_back(v[i]);
			return ans;
		}
		if (u <= maxi && maxi <= l)
		{
			vector<int>ans;
			for (int i = n - 1; i >= n - k; i--)
				ans.push_back(v[i]);
			return ans;
		}
		long long suma = 0;
		int j = k;
		int t = 0;
		for (int i = 0; i < k; i++)
			suma += w[v[i]];
		while (suma < l)
		{
			suma -= w[v[t]];
			suma += w[v[j]];
			t++;
			j++;
		}
		vector<int>ans;
		for (int i = t; i < j; i++)
			ans.push_back(v[i]);
		return ans;
	}
	return {};
}/*
int main() {
	int n, l, u;
	assert(3 == scanf("%d %d %d", &n, &l, &u));
	std::vector<int> w(n);
	for (int i = 0; i < n; i++)
		assert(1 == scanf("%d", &w[i]));
	std::vector<int> result = find_subset(l, u, w);


	printf("%d\n", (int)result.size());
	for (int i = 0; i < (int)result.size(); i++)
		printf("%d%c", result[i], " \n"[i == (int)result.size() - 1]);
}
/**/

Compilation message (stderr)

molecules.cpp:78:1: warning: "/*" within comment [-Wcomment]
 /**/
  
molecules.cpp: In function 'std::vector<int> find_subset(int, int, std::vector<int>)':
molecules.cpp:10:6: warning: unused variable 'a' [-Wunused-variable]
  int a = u - l;
      ^

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