Submission #276987

#	Time	Username	Problem	Language	Result	Execution time	Memory
276987		azret	Combo (IOI18_combo)	C++14	97 / 100	42 ms	684 KiB

combo

#include <cassert>

#include "combo.h"

using namespace std;

string L = "ABXY";

string guess_sequence(int N) {
  string ans = "";

  for (int i = 0; i < 4; i++) {
    string t = "";
    t += L[i];
    
    if (i == 3 || press(t) == 1) {
      swap(L[i], L[0]);
      break;
    }
  }

  ans += L[0];

  for (int i = 0; i < N - 2; i++) {
    int cl = 1 + i;

    string t = "";

    t += ans + L[1] + L[1];
    t += ans + L[1] + L[2];
    t += ans + L[1] + L[3];
    t += ans + L[2];

    // assert(((int) t.size()) <= 4 * N);

    int c = press(t);

    if (c == cl + 2) {
      ans += L[1];
    } else if (c == cl + 1) {
      ans += L[2];
    } else {
      ans += L[3];
    }
  }

  // assert(((int) ans.size()) == N - 1);

  if (((int) ans.size()) == N - 1) {
    for (int i = 1; i < 4; i++) {
      string t = ans;
      t += L[i];

      if (i == 3 || press(t) == N) {
        ans += L[i];
        break;
      }
    }
  }

  // assert(((int) ans.size()) == N);
  return ans;
}

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