Submission #820632

#	Time	Username	Problem	Language	Result	Execution time	Memory
820632		dashka	Combo (IOI18_combo)	C++14	100 / 100	25 ms	664 KiB

combo

#include <bits/stdc++.h>
 
std::string s;
std::vector<char> c;
 
int press(std::string);
 
std::string make(std::string cur){
	std::string ret;
	for(int i{}; i < 3; ++i){
		ret+=cur;
		ret.push_back(c[0]);
		ret.push_back(c[i]);
	}
	ret+=cur;
	ret.push_back(c[1]);
	return ret;
}
 
std::string guess_sequence(int n){
	int val=press("AB");
	if(val)
		s=(press("A")==1?"A":"B");
	else
		s=(press("X")==1?"X":"Y");
	std::string all{"ABXY"};
	for(char ch: all)
		if(s[0]!=ch)
			c.push_back(ch);
	while(s.size()<n-1){
		int k=s.size();
		int cur=press(make(s));
		if(cur==k)
			s.push_back(c[2]);
		else if(cur==k+1)
			s.push_back(c[1]);
		else s.push_back(c[0]);
	}
	if(s.size()==n-1){
		std::string curs=s;
		curs.push_back(c[0]);
		curs+=s;
		curs.push_back(c[1]);
		if(press(curs)==n-1)
			s.push_back(c[2]);
		else{
			curs=s;
			curs.push_back(c[0]);
			if(press(curs)==n)
				s.push_back(c[0]);
			else
				s.push_back(c[1]);
		}
	}
	return s;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:30:16: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   30 |  while(s.size()<n-1){
      |        ~~~~~~~~^~~~
combo.cpp:39:13: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   39 |  if(s.size()==n-1){
      |     ~~~~~~~~^~~~~

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