Submission #96609

#	Time	Username	Problem	Language	Result	Execution time	Memory
96609		diamond_duke	Combo (IOI18_combo)	C++11	100 / 100	178 ms	572 KiB

combo

#include "combo.h"
#include <algorithm>
std::string guess_sequence(int n)
{
	std::string str = press("AB") ?
					  (press("A") ? "A" : "B") :
					  (press("X") ? "X" : "Y");
	if (n == 1)
		return str;
	std::string alpha = "ABXY";
	for (int i = 0; i < 4; i++)
	{
		if (alpha[i] == str[0])
			std::swap(alpha[i], alpha[3]);
	}
	for (int i = 1; i + 1 < n; i++)
	{
		auto qry = str + alpha[1] +
				   str + alpha[2] + alpha[0] +
				   str + alpha[2] + alpha[1] +
				   str + alpha[2] + alpha[2];
		int res = press(qry);
		if (res == str.size())
			str += alpha[0];
		else if (res == str.size() + 1)
			str += alpha[1];
		else
			str += alpha[2];
	}
	if (press(str + alpha[0]) == str.size() + 1)
		str += alpha[0];
	else if (press(str + alpha[1]) == str.size() + 1)
		str += alpha[1];
	else
		str += alpha[2];
	return str;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:23:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |   if (res == str.size())
      |       ~~~~^~~~~~~~~~~~~
combo.cpp:25:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |   else if (res == str.size() + 1)
      |            ~~~~^~~~~~~~~~~~~~~~~
combo.cpp:30:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |  if (press(str + alpha[0]) == str.size() + 1)
      |      ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
combo.cpp:32:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |  else if (press(str + alpha[1]) == str.size() + 1)
      |           ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~

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