Submission #1355418

#	Time	Username	Problem	Language	Result	Execution time	Memory
1355418		seasonz	Combo (IOI18_combo)	C++20	0 / 100	0 ms	344 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
string find_first()
{
  if (press("AB"))
  {
    if (press("A")) return "A";
    else return "B";
  }
  else
  {
    if (press("X")) return "X";
    else return "Y";
  }
}
string find_last(string &past, int N, vector<string> &avail)
{
  if (press(past + avail[0]) == N) return avail[0];
  if (press(past + avail[1]) == N) return avail[1];
  if (press(past + avail[2]) == N) return avail[2];

}
void add_next(string &cur, vector<string> &avail, int &now, int N)
{
  if (cur.size() == N-1) return;
  string ttry = cur + avail[0] + avail[0] + cur + avail[0] + avail[1] + cur + avail[0] + avail[2] + cur + avail[1];
  int out = press(ttry);
  cur += avail[2-out+now];
  now++;
  add_next(cur, avail, now, N);
}
string guess_sequence(int N) {
  vector<string> vv = {"A", "B", "X", "Y"};
  vector<string> avail;
  string first = find_first();
  for (string ch : vv) if (ch != first) avail.push_back(ch);
  string cur = "" + first;
  int now = 1;
  add_next(cur, avail, now, N);
  cur += find_last(cur, N, avail);
  cout << cur;
  return cur;
}

Compilation message (stderr)

combo.cpp: In function 'std::string find_last(std::string&, int, std::vector<std::__cxx11::basic_string<char> >&)':
combo.cpp:23:1: warning: control reaches end of non-void function [-Wreturn-type]
   23 | }
      | ^

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