Submission #96130

#	Time	Username	Problem	Language	Result	Execution time	Memory
96130		kitsu_hi	Combo (IOI18_combo)	C++14	100 / 100	49 ms	520 KiB

combo

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

string guess_sequence(int N) {
  string ans;
  ans.clear();
  if ( press("AB") ) {
    if ( press("A") ) ans += 'A';
    else ans += 'B';
  }
  else {
    if ( press("X") ) ans += 'X';
    else ans += 'Y';
  }
  if ( N == 1 )  return ans;

  set<char> c_;
  char c[4];
  c_.insert('A');
  c_.insert('B');
  c_.insert('X');
  c_.insert('Y');
  c_.erase(ans[0]);
  auto it = c_.begin();
  for ( int i = 1; i <= 3; i++ ) {
    c[i] = *it;
    it++; 
  }
  
  for ( int j = 2 ; j < N; j++ ) {
    string ct;
    ct.clear();
    for ( int i = 1; i <= 3; i++ ) {
      ct = ct + ans + c[1] + c[i];
    }
    ct = ct + ans + c[2];
    int x = press(ct);
    if ( x == j - 1) ans += c[3];
    if ( x == j ) ans += c[2];
    if ( x == j + 1 ) ans += c[1];
  }

  if ( press( ans + c[1] + ans + c[2] ) == N ) {
    if ( press( ans + c[1]) == N ) ans += c[1];
    else ans += c[2];
  }
  else {
    ans += c[3];
  }
  return ans;
}

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