Submission #963458

#	Time	Username	Problem	Language	Result	Execution time	Memory
963458		The_Samurai	Combo (IOI18_combo)	C++17	30 / 100	22 ms	1472 KiB

combo

#include "combo.h"
#include "bits/stdc++.h"
using namespace std;

random_device rd;
mt19937_64 mt(rd());

void shuffle(string &s) {
  for (int i = 1; i < s.size(); i++) swap(s[rand() % (i + 1)], s[i]);
}

string guess_sequence(int n) {
  string ans = "", s = "ABXY";
  shuffle(s);
  for (int i = 0; i < 3; i++) {
    ans += s[i];
    if (press(ans)) break;
    ans.pop_back();
  }
  if (ans.empty()) ans += s.back();
  s.erase(find(s.begin(), s.end(), ans[0]));
  for (int ln = 2; ln <= n; ln++) {
    shuffle(s);
    for (int i = 0; i < 2; i++) {
      ans += s[i];
      if (press(ans) == ln) break;
      ans.pop_back();
    }
    if (ans.size() != ln) ans += s.back();
  }
  return ans;
}

Compilation message (stderr)

combo.cpp: In function 'void shuffle(std::string&)':
combo.cpp:9:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 |   for (int i = 1; i < s.size(); i++) swap(s[rand() % (i + 1)], s[i]);
      |                   ~~^~~~~~~~~~
combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:29:20: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   29 |     if (ans.size() != ln) ans += s.back();
      |         ~~~~~~~~~~~^~~~~

• Subtask 1: 5 / 5
• Subtask 2: 25 / 95