Submission #1066738

#	Time	Username	Problem	Language	Result	Execution time	Memory
1066738		Muhammad_Aneeq	Combo (IOI18_combo)	C++17	100 / 100	45 ms	11912 KiB

combo

#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
char d[4]={'A','B','X','Y'};
map<string,int>vis;
int ask(string x)
{
	if (vis.find(x)==vis.end())
		vis[x]=press(x);
	return vis[x];
}
string guess_sequence(int N)
{
	srand(time(0));
	string init="";
	string g="AB",y="AX";
	if (ask(g)&&ask(y))
		init+='A';
	if (ask(g)&&!ask(y))
		init+='B';
	if (!ask(g)&&ask(y))
		init+='X';
	if (!ask(g)&&!ask(y))
		init+='Y';
	vector<int>c;
	for (int i=0;i<4;i++)
	{
		if (init[0]==d[i])
			continue;
		c.push_back(d[i]);
	}
	for (int i=1;i<N;i++)
	{
		if (i!=N-1)
		{
			string z;
			z+=init;
			z+=c[0];
			string g;
			g+=init;
			g+=c[1];
			for (int j=0;j<3;j++)
				z+=g,z+=c[j];
			int sz=ask(z);
			if (sz==i)
				init+=c[2];
			if (sz==i+1)
				init+=c[0];
			if (sz==i+2)
				init+=c[1];
		}
		else
		{
			for (int j=0;j<2;j++)
			{
				init+=c[j];
				if (ask(init)==i+1)
					break;
				init.pop_back();
			}
			if (init.size()==i)
				init+=c[2];
		}
	}
	return init;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:61:19: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   61 |    if (init.size()==i)
      |        ~~~~~~~~~~~^~~

• Subtask 1: 5 / 5
• Subtask 2: 95 / 95