Submission #813804

#	Time	Username	Problem	Language	Result	Execution time	Memory
813804		joonwu04	Counting Mushrooms (IOI20_mushrooms)	C++17	92.24 / 100	7 ms	340 KiB

mushrooms

#include "mushrooms.h"
#include <vector>
#include <iostream>

using namespace std;


vector<int> a, b;
int ans;

int type3(vector<int> &v);
void type2(int base1, int base2, int isA, int i, int j);
void type1(int i);

int count_mushrooms(int n) {
	if(n==2) {
		return 2-use_machine({0, 1});
	}
	
	//printf("printOK\n");
	
	a.push_back(0);
	type1(1);
	type1(2);
	//printf("pass1\n");
	
	int k=min(n-1, 140);
	k -= k%2==1 ? 1:0;
	// k%2 == 0
	for(int i=3; i<=k-1; i+=2) {
		if(a.size()>=2) {
			type2(a[0], a[1], 1, i, i+1);
		}
		else {
			type2(b[0], b[1], 0, i, i+1);
		}
	}
	//printf("pass2\n");
	
	ans = a.size();
	
	int i=k+1;
	while(i<=n-1) {
		int vSize = min(n-1-i+1, (int)max(a.size(), b.size()));
		
		vector<int> v;
		for(int j=0; j<vSize; j++) {
			v.push_back(i+j);
		}
		
		ans += type3(v);
		
		//printf("%d~%d pass\n", i, i+vSize-1);
		i = i+vSize;
	}
	
	return ans;
}

// type3: knowing v by 1 with how many colors are red.
int type3(vector<int> &v) {
	int isA = a.size() >= b.size() ? 1:0;
	vector<int> &ta = isA ? a:b;
	vector<int> &tb = isA ? b:a;
	
	vector<int> tmp;
	for(int i=0; i<v.size(); i++) {
		tmp.push_back(ta[i]);
		tmp.push_back(v[i]);
	}
	
	int x = use_machine(tmp);
	
	if(x%2 == 0) {
		ta.push_back(v.back());
	}
	else {
		tb.push_back(v.back());
	}
	
	int numA = 0;
	if(x%2 == 0) {
		numA++;
		numA += v.size()-1 - x/2;
	}
	else {
		numA += v.size()-1 - (x-1)/2;
	}
	
	return isA ? numA : v.size()-numA;
}

// type2: knowing 2 by 1 with what color is. And push each of them into red or blue.
void type2(int base1, int base2, int isA, int i, int j) {
	int x = use_machine({base1, i, base2, j});
	
	vector<int> &ta = isA ? a:b;
	vector<int> &tb = isA ? b:a;
	if(x == 0) {
		ta.push_back(i);
		ta.push_back(j);
	}
	else if(x == 1) {
		ta.push_back(i);
		tb.push_back(j);
	}
	else if(x == 2) {
		tb.push_back(i);
		ta.push_back(j);
	}
	else {
		tb.push_back(i);
		tb.push_back(j);
	}
}

// type1: knowing 1 by 1 with what color is. And push it into red or blue.
void type1(int i) {
	if(use_machine({0, i}) == 0) {
		a.push_back(i);
	}
	else {
		b.push_back(i);
	}
}

Compilation message (stderr)

mushrooms.cpp: In function 'int type3(std::vector<int>&)':
mushrooms.cpp:67:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   67 |  for(int i=0; i<v.size(); i++) {
      |               ~^~~~~~~~~

• Subtask 1: 92.2449 / 100