Submission #574629

#	Time	Username	Problem	Language	Result	Execution time	Memory
574629		KrisjanisP	Combo (IOI18_combo)	C++14	100 / 100	32 ms	612 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

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

  if (press("AB") >= 1)
  {
    if (press("A") == 1)
      res = "A";
    else
      res = "B";
  }
  else
  {
    if (press("X") == 1)
      res = "X";
    else
      res = "Y";
  }

  if (N == 1)
    return res;

  char a[3] = {'A', 'B', 'X'};
  for (ll i = 0; i < 3; i++)
    if (a[i] == res[0])
      a[i] = 'Y';

  for (ll i = 1; i < N - 1; i++)
  {
    string query = "";
    query += res + a[0];
    for (ll j = 0; j < 3; j++)
      query += res + a[1] + a[j];
    ll w = press(query), p = res.size();
    if (w == p + 1)
      res += a[0];
    else if (w == p + 2)
      res += a[1];
    else
      res += a[2];
  }

  if(press(res+a[0]+res+a[1])==N)
    if(press(res+a[0])==N) res+=a[0];
    else res+=a[1];
  else
    res += a[2];

  return res;
}

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