Submission #237698

#	Time	Username	Problem	Language	Result	Execution time	Memory
237698		lucifer1004	Combo (IOI18_combo)	C++17	5 / 100	1 ms	276 KiB

combo

#include <iostream>
#include <set>
#include <vector>

using namespace std;

int press(string s);

string guess_sequence(int N) {
  string ans;
  int ab = press("AB");
  if (ab == 0) {
    int x = press("X");
    if (x == 0)
      ans += "Y";
    else
      ans += "X";
  } else {
    int a = press("A");
    if (a == 0)
      ans += "B";
    else
      ans += "A";
  }
  set<char> s = {'A', 'B', 'X', 'Y'};
  s.erase(ans[0]);
  vector<char> sv(s.begin(), s.end());
  for (int i = 2; i < N; ++i) {
    string a(ans), b(ans);
    a.push_back(sv[0]);
    b.push_back(sv[1]);
    string a1(a), a2(a), a3(a);
    a1.push_back(sv[0]);
    a2.push_back(sv[1]);
    a3.push_back(sv[2]);
    int q = press(a1 + a2 + a3 + b);
    if (q == i + 1)
      ans.push_back(sv[0]);
    if (q == i)
      ans.push_back(sv[1]);
    if (q == i - 1)
      ans.push_back(sv[2]);
  }
  string a(ans), b(ans);
  a.push_back(sv[0]);
  int qa = press(a);
  if (qa == N)
    return a;
  b.push_back(sv[1]);
  int qb = press(b);
  if (qb == N)
    return b;
  ans.push_back(sv[2]);
  return ans;
}

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