Submission #785823

#	Time	Username	Problem	Language	Result	Execution time	Memory
785823		Boas	Combo (IOI18_combo)	C++17	5 / 100	3025 ms	608 KiB

combo

#include "combo.h"

#include <bits/stdc++.h>
#define ALL(x) x.begin(), x.end()
using namespace std;

string guess_sequence(int N)
{
  vector<char> buttons = {'A', 'B', 'X', 'Y'};
  string S;
  random_device rd;
  mt19937 g(rd());
  uniform_int_distribution<int> dist(0, 2);
  while (S.size() < N)
  {
    shuffle(buttons.begin(), buttons.end(), g);
    for (int c = 0; c < buttons.size(); c++)
    {
      string p = S + buttons[c];
      if (c == buttons.size() - 1)
      {
        S = p;
        if (S.size() == 1)
        {
          buttons.erase(find(ALL(buttons), buttons[c]));
          if (buttons.size() != 3)
            throw;
        }
        break;
      }
      else
      {
        if (S.size() > 0)
        {
          while (p.size() < 4 * N)
          {
            int rand = 0;
            rand = dist(rd);
            p += buttons[rand];
          }
        }
        int res = press(p);
        if (res > S.size())
        {
          S = string(p.begin(), p.begin() + res);
          if (S.size() == 1)
          {
            buttons.erase(find(ALL(buttons), buttons[c]));
            if (buttons.size() == 4)
              throw;
          }
          break;
        }
      }
    }
  }
  return S;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:14:19: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   14 |   while (S.size() < N)
      |          ~~~~~~~~~^~~
combo.cpp:17:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |     for (int c = 0; c < buttons.size(); c++)
      |                     ~~^~~~~~~~~~~~~~~~
combo.cpp:20:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |       if (c == buttons.size() - 1)
      |           ~~^~~~~~~~~~~~~~~~~~~~~
combo.cpp:35:27: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   35 |           while (p.size() < 4 * N)
      |                  ~~~~~~~~~^~~~~~~
combo.cpp:43:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |         if (res > S.size())
      |             ~~~~^~~~~~~~~~

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