Submission #398342

#	Time	Username	Problem	Language	Result	Execution time	Memory
398342		kevinxiehk	Combo (IOI18_combo)	C++17	100 / 100	62 ms	568 KiB

combo

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

string guess_sequence(int n) {
  string p = "";
  string lef = "";
  int a = press("AB");
  if(a >= 1) {
    a = press("A");
    p = (a == 1 ? "A" : "B");
    lef = (a == 1 ? "BXY" : "AXY");
  }
  else {
    a = press("X");
    p = (a == 1 ? "X" : "Y");
    lef = (a == 1 ? "ABY" : "ABX");
  }
  for(int i = 2; i < n; i++) {
    string guess = "";
    guess += p;
    guess += lef[0];
    guess += lef[0];
    guess += p;
    guess += lef[0];
    guess += lef[1];
    guess += p;
    guess += lef[0];
    guess += lef[2];
    guess += p;
    guess += lef[1];
    a = press(guess);
    if(a - p.length() == 0) {
      p += lef[2];
    }
    else if(a - p.length() == 1) {
      p += lef[1];
    }
    else p += lef[0];
  }
  if(n >= 2) {
    a = press(p + lef[0] + p + lef[1]);
    if(a - p.length() == 0) p += lef[2];
    else {
      a = press(p + lef[0]);
      if(a - p.length() == 0) p += lef[1];
      else p += lef[0];
    }
  }
  return p;
}

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