Submission #1208948

#	Time	Username	Problem	Language	Result	Execution time	Memory
1208948		thewizardman	Combo (IOI18_combo)	C++20	5 / 100	0 ms	408 KiB

combo

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

string str[3] = {"BB", "XB", "XX"};
string mt[3][3] = {
  {"Y", "Y", "Y"},
  {"XY", "BX", "BY"},
  {"BB", "XB", "XX"}
};

string guess_sequence(int n) {
  string s;
  if (press("AB")) {
    if (press("A")) s += "A";
    else s += "B";
  } else {
    if (press("X")) s += "X";
    else s += "Y";
  }
  for (auto& st: str) for (auto& c: st) if (c == s[0]) c = 'A';
  for (auto& a: mt) for (auto& st: a) for (auto& c: st) if (c == s[0]) c = 'A';

  if (n == 2) {
    if (press(s + "AB") > s.length()) {
      if (press(s + "A") > s.length()) s += "A";
      else s += "B";
    } else {
      if (press(s + "X") > s.length()) s += "X";
      else s += "Y";
    }
  }

  while (s.length() < n) {
    string p;
    for (auto st: str) p += s + st;
    int i = press(p) - s.length();
    if (i == 0) {
      s += mt[0][0];
    } else {
      s += mt[i][press(s + mt[i][2]) - s.length()];
    }
  }
  if (s.length() == n+1) s.pop_back();
  return s;
}

/*
  wlog a is first
    bb xb xx
    0 -> yb yx yy
    1 -> bx by xy
    2 -> bb xb xx
*/

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