Submission #407414

#	Time	Username	Problem	Language	Result	Execution time	Memory
407414		ngrace	Combo (IOI18_combo)	C++14	97 / 100	42 ms	584 KiB

combo

#include "combo.h"
#include <string>
#include <vector>
#include <iostream>
using namespace std;

std::string guess_sequence(int N) {
  vector<char> but = {'A','B','X','Y'};
  string s = "";

  //find first
  char start='1';
  for(char c : but){
    if(c=='Y'){
      s.push_back(c);
      start=c;
      break;
    }
    if(press(string(1,c))==1){
      s.push_back(c);
      start=c;
      break;
    }
  }

  if(start=='A'){
    but={'B','X','Y'};
  }
  else if(start=='B'){
    but={'A','X','Y'};
  }
  else if(start=='X'){
    but={'A','B','Y'};
  }
  else{
    but={'A','B','X'};
  }

  for(int i=1;i<N-1;i++){
    string q="";
    q.append(s);
    q.push_back(but[0]);
    q.append(s);
    q.push_back(but[1]);
    q.push_back(but[0]);
    q.append(s);
    q.push_back(but[1]);
    q.push_back(but[1]);
    q.append(s);
    q.push_back(but[1]);
    q.push_back(but[2]);
    //cout<<q<<endl;
    int qu=press(q);
    if(qu==i+0){
      s.push_back(but[2]);
    }
    else if(qu==i+1){
      s.push_back(but[0]);
    }
    else{
      s.push_back(but[1]);
    }
    //cout<<qu<<endl;
    //cout<<s.back()<<endl;
  }

  //now get last element
  if(s.size()<N){
    for(int i=0;i<2;i++){
      s.push_back(but[i]);
      if(press(s)==N){
        break;
      }
      s.pop_back();
    }
    if(s.size()<N){
      s.push_back(but[2]);
    }
  }
  //cout<<s<<endl;
  return s;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:68:14: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   68 |   if(s.size()<N){
      |      ~~~~~~~~^~
combo.cpp:76:16: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   76 |     if(s.size()<N){
      |        ~~~~~~~~^~

• Subtask 1: 5 / 5
• Subtask 2: 92 / 95