Submission #303549

#	Time	Username	Problem	Language	Result	Execution time	Memory
303549		galca	Counting Mushrooms (IOI20_mushrooms)	C++14	63.31 / 100	14 ms	416 KiB

mushrooms

#include "mushrooms.h"

using namespace std;

int count_mushrooms(int n) {
	vector<int> knownZeros;
	vector<int> knownOnes;

	knownZeros.push_back(0);

	vector<int> pairs;
	pairs.push_back(0);
	pairs.push_back(0);

	if (n <= 128) {
		for (int i = 1; i < n; i++) {
			pairs[1] = i;
			int c = use_machine(pairs);
			if (c) {
				knownOnes.push_back(i);
			}
			else {
				knownZeros.push_back(i);
			}
		}
		return knownZeros.size();
	}

	for (int i = 1; i < 128; i++) {
		pairs[1] = i;
		int c = use_machine(pairs);
		if (c) {
			knownOnes.push_back(i);
		}
		else {
			knownZeros.push_back(i);
		}
	}

	int i = 128;
	int totalZeros = knownZeros.size();

	while (i < n) {
		vector<int> m;
		if (knownOnes.size() >= knownZeros.size()) {
			
			for (int j = 0; j < knownOnes.size(); j++) {
				if ((i + j) < n) {
					m.push_back(knownOnes[j]);
					m.push_back(i + j);
				}
			}
			int c = use_machine(m);
			if (c & 1) {
				++totalZeros;
				--c;
				knownZeros.push_back(m[m.size() - 1]);
			}
			totalZeros += c / 2;
			i += knownOnes.size();
		}
		else {
			for (int j = 0; j < knownZeros.size(); j++) {
				if ((i + j) < n) {
					m.push_back(knownZeros[j]);
					m.push_back(i + j);
				}
			}
			int c = use_machine(m);
			if (c & 1) {
				++c;
				knownOnes.push_back(m[m.size() - 1]);
			}
			totalZeros += (m.size() - c) / 2;
			i += knownZeros.size();
		}
	}
	return totalZeros;
}

Compilation message (stderr)

mushrooms.cpp: In function 'int count_mushrooms(int)':
mushrooms.cpp:47:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |    for (int j = 0; j < knownOnes.size(); j++) {
      |                    ~~^~~~~~~~~~~~~~~~~~
mushrooms.cpp:63:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |    for (int j = 0; j < knownZeros.size(); j++) {
      |                    ~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 63.3053 / 100