Submission #1006865

#	Time	Username	Problem	Language	Result	Execution time	Memory
1006865		adrielcp	Combo (IOI18_combo)	C++17	30 / 100	29 ms	1116 KiB

combo

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

// int press(string hm) {
//   cout << hm << endl;
//   int ans;cin>>ans;
//   return ans;
// }

string S = "ABXY";

char getpatokan() {
  int res1 = press("AB"), res2 = press("BX");
  if (res1 && res2) return 'B';
  else if (res1) return 'A';
  else if (res2) return 'X';
  else return 'Y';
}

// ABXYBYYXB
// patokan: A
// BXYBYYXB
// ABAX
// AXAY
//
string guess_sequence(int n) {
  char patokan = getpatokan();
  set<char> st{'A', 'B', 'X', 'Y'};
  st.erase(patokan);
  string now;
  now += patokan;
  for (int i = 0; i < n-1; i++) {
    auto it = st.begin();
    int idx = rand()%3;
    char gok = 'O';
    char top;
    for (int j = 0; j < 3; j++) {
      char x = *it;
      it++;
      if (j == idx) {
        top = x;
        continue;
      }
      if (press(now + x) == now.length()+1) {
        gok = x;
        break;
      }
    } 

    if (gok == 'O') now += top;
    else now += gok;
  }

  return now;
}

// int main() {
//   int n;cin>>n;
//   cout << guess_sequence(n) << endl;
// }

// string guess_sequence(int N) {
//   string permu = "AAAABBBBXXXXYYYY";
//   do {
//     cout << permu << endl;
//   } while (next_permutation(all(permu)));
// }

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:46:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |       if (press(now + x) == now.length()+1) {
      |           ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~

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