Submission #251910

#	Time	Username	Problem	Language	Result	Execution time	Memory
251910		paradox	Combo (IOI18_combo)	C++17	100 / 100	41 ms	724 KiB

combo

#include "combo.h"

#include <iostream>
#include <fstream>
#include <vector>
#include <set>
#include <map>
#include <cstring>
#include <string>
#include <cmath>
#include <cassert>
#include <ctime>
#include <algorithm>
#include <sstream>
#include <list>
#include <queue>
#include <deque>
#include <stack>
#include <cstdlib>
#include <cstdio>
#include <iterator>
#include <functional>
#include <unordered_set>
#include <unordered_map>
using namespace std;

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define pii pair<int, int>
#define vi vector<int>
#define fast_io ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)

char ch[] = {'A', 'B', 'X', 'Y'};

char findNextCharacter(string currentString) {
  int f = 0, s = 1;
  string query = currentString + ch[f] + currentString + ch[s];
  int res = press(query);
  if (res == sz(currentString))
    f = 2, s = 3;
  
  query = currentString + ch[f];
  res = press(query);

  return (res != sz(currentString) ? ch[f] : ch[s]);
}
string guess_sequence(int N) {
  char first = findNextCharacter("");
  string ans = "";

  ans += first;

  string buttons = "";

  for (int i = 0; i < 4; ++i)
    if (first != ch[i])
      buttons += ch[i];

  for (int i = 2; i < N; ++i) {
    string query = "";
    query = ans + buttons[1];
    for (int j = 0; j < 3; ++j)
      query += ans + buttons[2] + buttons[j];
    
    int res = press(query);

    if (res == i - 1)
      ans += buttons[0];
    else if (res == i)
      ans += buttons[1];
    else 
      ans += buttons[2];
  }
  
  if (N > 1) {
    char last = findNextCharacter(ans);
    ans += last;
  }
  return ans;
}

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