Submission #963862

#	Time	Username	Problem	Language	Result	Execution time	Memory
963862		TAhmed33	Combo (IOI18_combo)	C++17	100 / 100	17 ms	1960 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
char getfirst () {
  string u = "AB";
  int y = press(u);
  if (y >= 1) {
    u = "A";
    y = press(u);
    if (y == 1) return 'A';
    return 'B';
  } else {
    u = "X";
    y = press(u);
    if (y == 1) return 'X';
    return 'Y';
  }
}
string guess_sequence (int n) {
  char x = getfirst();
  vector <char> dd = {'A', 'B', 'X', 'Y'};
  for (int i = 0; i < 4; i++) {
    if (dd[i] == x) {
      dd.erase(dd.begin() + i);
    }
  }
  string ret; ret += x;
  if (n == 1) return ret;
  for (int i = 2; i < n; i++) {
    string f1 = ret; f1 += dd[0]; f1 += dd[0];  
    string f2 = ret; f2 += dd[0]; f2 += dd[1];  
    string f3 = ret; f3 += dd[0]; f3 += dd[2];  
    string f4 = ret; f4 += dd[1];
    string g = f1 + f2 + f3 + f4;
    int y = press(g); 
    if (y == i - 1) {
      ret += dd[2];
    }  else if (y == i) {
      ret += dd[1];
    } else {
      ret += dd[0];
    }
  }
  for (int i = 0; i < 2; i++) {
    string u = ret; u += dd[i];
    int g = press(u);
    if (g == n) {
      ret = u;
      break;
    }
    if (i == 1) ret += dd[2];
  }
  return ret;
}

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