Submission #436417

#	Time	Username	Problem	Language	Result	Execution time	Memory
436417		stoyan_malinin	Combo (IOI18_combo)	C++14	100 / 100	77 ms	2604 KiB

combo

#include <algorithm>
#include <iostream>
#include <vector>
#include <string>

#include "combo.h"
#ifdef __LOCAL
#include "grader.cpp"
#endif // __LOCAL

using namespace std;

char extend(string &ans, bool isLast = false)
{
    vector <char> options = {'A', 'B', 'X', 'Y'};
    if(ans.size()!=0)
        options.erase(find(options.begin(), options.end(), ans[0]));

    cerr << "-> " << ans << '\n';

    if(ans.size()==0)
    {
        if(press("AB")>=1)
        {
            if(press("A")>=1) return 'A';
            return 'B';
        }
        else
        {
            if(press("X")>=1) return 'X';
            return 'Y';
        }
    }
    else if(isLast==false)
    {
        int res = press(ans+options[0]+options[0]+ans+options[0]+options[1]+ans+options[0]+options[2]+ans+options[1]);
        if(res==ans.size()+2) return options[0];
        if(res==ans.size()+1) return options[1];
        if(res==ans.size()+0) return options[2];
    }
    else
    {
        int res = press(ans+options[0]+ans+options[1]);
        if(res==ans.size()) return options[2];

        res = press(ans+options[0]);
        if(res==ans.size()) return options[1];

        return options[0];
    }
}

string guess_sequence(int N)
{
    string ans = "";
    for(int i = 0;i<N-1;i++) ans += extend(ans);
    ans += extend(ans, true);

    return ans;
}

Compilation message (stderr)

combo.cpp: In function 'char extend(std::string&, bool)':
combo.cpp:37:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |         if(res==ans.size()+2) return options[0];
      |            ~~~^~~~~~~~~~~~~~
combo.cpp:38:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |         if(res==ans.size()+1) return options[1];
      |            ~~~^~~~~~~~~~~~~~
combo.cpp:39:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |         if(res==ans.size()+0) return options[2];
      |            ~~~^~~~~~~~~~~~~~
combo.cpp:44:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |         if(res==ans.size()) return options[2];
      |            ~~~^~~~~~~~~~~~
combo.cpp:47:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |         if(res==ans.size()) return options[1];
      |            ~~~^~~~~~~~~~~~
combo.cpp:15:48: warning: control reaches end of non-void function [-Wreturn-type]
   15 |     vector <char> options = {'A', 'B', 'X', 'Y'};
      |                                                ^

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