Submission #1012988

#	Time	Username	Problem	Language	Result	Execution time	Memory
1012988		aufan	Combo (IOI18_combo)	C++17	100 / 100	20 ms	2072 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>

using namespace std;
string guess_sequence(int N) {
  string ans = "";
  vector<string> ask;
  if (press("AB") >= 1) {
    if (press("A")) {
      ans += "A";
      ask = {"B", "X", "Y"};
    } else {
      ans += "B";
      ask = {"A", "X", "Y"};
    }
  } else {
    if (press("X")) {
      ans += "X";
      ask = {"A", "B", "Y"};
    } else {
      ans += "Y";
      ask = {"A", "B", "X"};
    }
  }
  if (N == 1) return ans;
  for (int i = 2; i <= N - 1; i++) {
    string x = ans + ask[0];
    string tp = "";
    for (int j = 0; j < 3; j++) {
      tp += x + ask[j];
    }
    tp += ans + ask[1];
    int ret = press(tp);
    if (ret == i + 1) ans += ask[0];
    else if (ret == i) ans += ask[1];
    else if (ret == i - 1) ans += ask[2];
  }
  if (press(ans + ask[0]) == N) ans += ask[0];
  else if (press(ans + ask[1]) == N) ans += ask[1];
  else ans += ask[2];
  return ans;
}

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