Submission #304336

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
304336	2020-09-21T06:33:59 Z	galca	Counting Mushrooms (IOI20_mushrooms)	C++14	0 / 100	0 ms	256 KB

mushrooms

#include "mushrooms.h"

using namespace std;

vector<int> knownZeros;
vector<int> knownOnes;
vector<int> alternating;

void resolveAlternating(int lastVal) {
	if (alternating.size() > 0) {
		if (lastVal == -1) {
			lastVal = use_machine({ 0, alternating[alternating.size()-1] });
		}
		else {
			if (alternating.size() > 0) {
				alternating.pop_back();
				lastVal ^= 1;
			}
		}

		while (alternating.size() > 0) {
			if (lastVal) {
				knownOnes.push_back(alternating[alternating.size() - 1]);
			}
			else {
				knownZeros.push_back(alternating[alternating.size() - 1]);
			}
			lastVal ^= 1;
			alternating.pop_back();
		}
	}
}

int count_mushrooms(int n) {
	knownZeros.push_back(0);
	// find one more, or two 1s
	int i = 1;
	while ((knownZeros.size() < 2) && (knownOnes.size() < 2)) {
		int c = use_machine({ 0, i });
		if (c) {
			knownOnes.push_back(i);
		}
		else {
			knownZeros.push_back(i);
		}
		++i;
		if (i == n) {
			return knownZeros.size();
		}
	}

	vector<int> fives;
	bool isZero = false;

	if (knownZeros.size() == 2) {
		fives.push_back(0);
		fives.push_back(knownZeros[0]);
		fives.push_back(0);
		fives.push_back(knownZeros[1]);
		fives.push_back(0);
		isZero = true;
	}
	else {
		fives.push_back(0);
		fives.push_back(knownOnes[0]);
		fives.push_back(0);
		fives.push_back(knownOnes[1]);
		fives.push_back(0);
	}

	while (((knownZeros.size() + alternating.size()/2) < 100) && 
		((knownOnes.size() + alternating.size() / 2) < 100)) {

		if (i == n) {
			return knownZeros.size();
		}
		if (i == (n - 1)) {
			int c = use_machine({ 0, n - 1 });
			return knownZeros.size() + 1 - c;
		}
		if (i == (n - 2)) {
			int c1 = use_machine({ 0, n - 1 });
			int c2 = use_machine({ 0, n - 2 });
			return knownZeros.size() + 2 - (c1+c2);
		}
		fives[0] = i;
		fives[2] = i + 1;
		fives[4] = i + 2;
		int c = use_machine(fives);
		int inc = 0;

		switch (c) {
			case 0:
				if (isZero) {
					knownZeros.push_back(i);
					knownZeros.push_back(i+1);
					knownZeros.push_back(i+2);
					resolveAlternating(0);
				}
				else {
					knownOnes.push_back(i);
					knownOnes.push_back(i + 1);
					knownOnes.push_back(i + 2);
					resolveAlternating(1);
				}
				i += 3;
				break;
			case 1:
				if (isZero) {
					knownZeros.push_back(i+1);
					if (alternating.size() == 0) {
						alternating.push_back(i);
					}
					alternating.push_back(i + 2);
				}
				else {
					knownOnes.push_back(i + 1);
					if (alternating.size() == 0) {
						alternating.push_back(i);
					}
					alternating.push_back(i + 2);
				}
				i += 2;
				break;
			case 2:
				if (isZero) {
					if (alternating.size() == 0) {
						alternating.push_back(i);
					}
					alternating.push_back(i + 1);
					alternating.push_back(i + 2);
				}
				else {
					if (alternating.size() == 0) {
						alternating.push_back(i);
					}
					alternating.push_back(i + 1);
					alternating.push_back(i + 2);
				}
				i += 2;
				break;
			case 3:
				if (isZero) {
					knownOnes.push_back(i+1);
					if (alternating.size() == 0) {
						alternating.push_back(i);
					}
					alternating.push_back(i + 2);
				}
				else {
					knownZeros.push_back(i + 1);
					if (alternating.size() == 0) {
						alternating.push_back(i);
					}
					alternating.push_back(i + 2);
				}
				i += 2;
				break;
			case 4:
				if (isZero) {
					knownOnes.push_back(i);
					knownOnes.push_back(i + 1);
					knownOnes.push_back(i + 2);
					resolveAlternating(1);
				}
				else {
					knownZeros.push_back(i);
					knownZeros.push_back(i + 1);
					knownZeros.push_back(i + 2);
					resolveAlternating(0);
				}
				i += 3;
				break;
		}
	}

	resolveAlternating(-1);
	i = knownZeros.size() + knownOnes.size();

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

Compilation message

mushrooms.cpp: In function 'int count_mushrooms(int)':
mushrooms.cpp:90:7: warning: unused variable 'inc' [-Wunused-variable]
   90 |   int inc = 0;
      |       ^~~
mushrooms.cpp:186:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  186 |    for (int j = 0; j < knownOnes.size(); j++) {
      |                    ~~^~~~~~~~~~~~~~~~~~
mushrooms.cpp:206:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  206 |    for (int j = 0; j < knownZeros.size(); j++) {
      |                    ~~^~~~~~~~~~~~~~~~~~~

Subtask #1

0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	256 KB	Output is correct
2	Correct	0 ms	256 KB	Output is correct
3	Incorrect	0 ms	256 KB	Answer is not correct.
4	Halted	0 ms	0 KB	-