Submission #574561

#	Time	Username	Problem	Language	Result	Execution time	Memory
574561		KrisjanisP	Combo (IOI18_combo)	C++14	5 / 100	1 ms	252 KiB

combo

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

using namespace std;
typedef long long ll;

string guess_sequence(int N) {
  if(N==2)
  {
    ll w = press("AB");
    if(w>=1)
    {
      if(w==2) return "AB";
      else if(w==1)
      {
        if(press("AX")==2) return "AX";
        else return "AY";
      }
      else{
        w = press("BA");
        if(w==2) return "BA";
        else
        {
          if(press("BX")==2) return "BX";
          else return "BY";
        }
      }
    }
    else
    {
      // XY
      w = press("XA");
      if(w==2) return "XA";
      else if(w==1){
        if(press("XB")==2) return "XB";
        else return "XY"; 
      }
      else{
        w = press("YA");
        if(w==2) return "YA";
        else
        {
          if(press("YB")==2) return "YB";
          else return "YX";
        }
      }
    }
  }
  string res = "";
  if(press("AB")>=1)
  {
    if(press("A")==1) res="A";
    else res="B";
  }
  else
  {
    if(press("X")==1) res="X";
    else res="Y";
  }

  char a[4] = {'A','B','X','Y'};

  for(ll i=res.size();i<N-1;i++)
  {
    string query = "";
    char f, s;
    for(ll j=0;j<4;j++)
    {
      if(a[j]==res[0]) continue;
      query += res;
      query += a[j];
      f = a[j];
      break;
    }
    for(ll j=0;j<4;j++)
    {
      if(a[j]==res[0]||a[j]==f) continue;
      for(ll k=0;k<4;k++)
      {
        if(a[k]==res[0]) continue;
        query+=res;
        query+=a[j];
        query+=a[k];
      }
      s = a[j];
      break;
    }
    ll w = press(query);
    if(w==(ll)res.size())
    {
      for(ll j=0;j<4;j++)
      {
        if(a[j]==res[0]||a[j]==f||a[j]==s) continue;
        res += a[j];
        break;
      }
    }
    else if(w==(ll)res.size()+1)
    {
      res += f;
    }
    else if(w==(ll)res.size()+2)
    {
      res += s;
    }
  }
  if(res.size()!=N)
  {
    bool found = false;
    for(ll i=0;i<3;i++)
    {
      if(a[i]==res[0]) continue;
      ll w = press(res+a[i]);
      if(w!=N) continue;
      found = true;
      res += a[i];
      break;
    }
    if(!found) res+=a[3];
  }
  return res;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:107:16: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  107 |   if(res.size()!=N)
      |      ~~~~~~~~~~^~~
combo.cpp:93:33: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]
   93 |         if(a[j]==res[0]||a[j]==f||a[j]==s) continue;
      |            ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 0 / 95