Submission #1021425

#	Time	Username	Problem	Language	Result	Execution time	Memory
1021425		elipsen	Combo (IOI18_combo)	C++17	5 / 100	0 ms	344 KiB

combo

#include "combo.h"
using namespace std;
#define str string
#define p press


str guess_sequence(int N) {
  str S[4] = {"A", "B", "X", "Y"};
  // Part 1: Determine the first letter (2)
  int initCombo = p("XYX") >= 1 ? 2 : 0;
  if (initCombo) {initCombo += p("XAXBXY") <= 1 ? 1 : 0;}
  else {initCombo += p("AXAYAB") <= 1 ? 1 : 0;}
  int lenCombo = 1;
  str combo = S[initCombo];
  for (int Si = initCombo; Si < 3; Si++) {S[Si] = S[Si + 1];}
  // Part 2: Determine letters between the first and last, if any (1 per)
  str query; int lenQuery;
  while (lenCombo < N - 1) {
    query = combo + S[0] + S[0] + 
                   combo + S[0] + S[1] + 
                   combo + S[0] + S[2] + 
                   combo + S[1];
    lenQuery = p(query);
    if (lenQuery == lenCombo + 2) {combo += S[0];}
    else if (lenQuery == lenCombo + 1) {combo += S[1];}
    else {combo += S[2];}
    lenCombo += 1;
  }
  // Part 3: Determine the last letter when necessary (2)
  if (lenCombo == N) {return combo;}
  else {
    if (p(combo + S[0]) == N) {return (combo + S[0]);}
    else if (p(combo + S[1]) == N) {return (combo + S[1]);}
    else {return (combo + S[2]);}
  }
}

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