Submission #1020879

#	Time	Username	Problem	Language	Result	Execution time	Memory
1020879		adrielcp	Combo (IOI18_combo)	C++17	100 / 100	25 ms	2164 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
#define all(x) x.begin(), x.end()
 
// int press(string hm) {
//   cout << hm << endl;
//   int ans;cin>>ans;
//   return ans;
// }
 
string S = "ABXY";
 
char getpatokan() {
  int res1 = press("AB"), res2 = press("BX");
  if (res1 && res2) return 'B';
  else if (res1) return 'A';
  else if (res2) return 'X';
  else return 'Y';
}
 
// ABXYBYYXB
// patokan: A
// BXYBYYXB
// guess 2 chars by 2 queries
 
// XX, BX, BY, YB -> 2
// XB, BB, XY, YX -> 1
 
// XXX
 
 
// AYY
 
 
string guess_sequence(int n) {
  if (n == 0) return "";
  char patokan = getpatokan();
  set<char> st{'A', 'B', 'X', 'Y'};
  st.erase(patokan);
  string now;
  now += patokan;
  vector<char> a(all(st));
  // cout << a << endl;
  for (int i = 0; i < n-2; i++) {
    // cout << now << endl;
    string s;
    for (int j = 0; j < 3; j++) s += now + a[0] + a[j];
    s += now + a[1];
    int x = press(s);
    if (x-now.size() == 0) now += a[2];
    else if (x - now.size() == 1) now += a[1];
    else now += a[0];
  }
  
  if (n >= 2) {
    for (int i = 0; i < 2; i++) {
      if (press(now + a[i]) == now.size()+1) {
        return now+a[i];
      }
    }
 
    return now + a[2];
  }
 
  return now;
}
 
// int main() {
//   int n;cin>>n;
//   cout << guess_sequence(n) << endl;
// }
 

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:58:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |       if (press(now + a[i]) == now.size()+1) {
      |           ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~

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