Submission #1033355

#	Time	Username	Problem	Language	Result	Execution time	Memory
1033355		happy_node	Counting Mushrooms (IOI20_mushrooms)	C++17	0 / 100	6 ms	616 KiB

mushrooms

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

const int B=50;

int count_mushrooms(int N) {
	vector<int> posA, posB;
	posA.push_back(0);
 	
 	if(use_machine({0,1})==0) posA.push_back(1);
 	else posB.push_back(1);

 	if(N>2) {
 		if(use_machine({0,2})==0) posA.push_back(2);
 		else posB.push_back(2);
 	}

	for(int i=3;i+1<min(N,2*B);i+=2) {
		if(posA.size()>=2) {
			vector<int> qry={posA[0],i,posA[1],i+1};
			int res=use_machine(qry);
			if(res==0) {
				posA.push_back(i);
				posA.push_back(i+1);
			} else if(res==1) {
				posA.push_back(i);
				posB.push_back(i+1);
			} else if(res==2) {
				posB.push_back(i);
				posA.push_back(i+1);
			} else {
				posB.push_back(i);
				posB.push_back(i+1);
			}
		} else {
			vector<int> qry={posB[0],i,posB[1],i+1};
			int res=use_machine(qry);
			if(res==0) {
				posB.push_back(i);
				posB.push_back(i+1);
			} else if(res==1) {
				posB.push_back(i);
				posA.push_back(i+1);
			} else if(res==2) {
				posA.push_back(i);
				posB.push_back(i+1);
			} else {
				posA.push_back(i);
				posA.push_back(i+1);
			}
		}

	}

	if((min(N,2*B)-1)&1) {
		if(use_machine({0,min(N,2*B)-1})==0) posA.push_back(min(N,2*B)-1);
		else posB.push_back(min(N,2*B)-1);
	}

	int ans=posA.size();

	for(int i=2*B;i<N;i++) {
		if(posA.size()>posB.size()) {
			int s=posA.size();
			vector<int> qry;
			for(int j=i;j<min(N,i+s);j++) {
				qry.push_back(posA[j-i]);
				qry.push_back(j);
			}	

			int w=use_machine(qry);
			if(w&1) posB.push_back(qry.back());
			else posA.push_back(qry.back());

			w=(w+1)/2;
			ans+=(qry.size()/2-w);
			i+=s-1;
		} else {
			int s=posB.size();
			vector<int> qry;
			for(int j=i;j<min(N,i+s);j++) {
				qry.push_back(posB[j-i]);
				qry.push_back(j);
			}	

			int w=use_machine(qry);
			if(w&1) posA.push_back(qry.back());
			else posB.push_back(qry.back());

			w=(w+1)/2;
			ans+=w;
			i+=s-1;
		}
	}
 
	return ans;
}

• Subtask 1: 0 / 100