Submission #75139

#	Time	Username	Problem	Language	Result	Execution time	Memory
75139		doowey	Combo (IOI18_combo)	C++14	100 / 100	57 ms	612 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>

using namespace std;

char ok[] = {'A', 'B', 'X', 'Y'};

string guess_sequence(int N) {
	string pref;
	if(press("AB") > 0){
		if(press("A"))
			pref += "A";
		else
			pref += "B";
	}
	else{
		if(press("X"))
			pref += "X";
		else
			pref += "Y";
	}
	vector<char> use;
	for(int i = 0;i < 4;i ++ ){
		if(pref[0] != ok[i])
			use.push_back(ok[i]);
	}
	string as;
	int sum;
	for(int i = 0;i < N-2; i ++ ){
		as = pref + use[0] + pref + use[1] + use[0] + pref + use[1] + use[1] + pref + use[1] + use[2];
		sum = press(as);
		if(sum == pref.size() + 1)
			pref += use[0];
		else if(sum == pref.size() + 2)
			pref += use[1];
		else
			pref += use[2];
	}
	if(N == 1)
		return pref;
	if(press(pref + use[0]) == N)
		return pref + use[0];
	else if(press(pref + use[1]) == N)
		return pref + use[1];
	else
		return pref + use[2];
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:32:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |   if(sum == pref.size() + 1)
      |      ~~~~^~~~~~~~~~~~~~~~~~
combo.cpp:34:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |   else if(sum == pref.size() + 2)
      |           ~~~~^~~~~~~~~~~~~~~~~~

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