Submission #281713

#	Time	Username	Problem	Language	Result	Execution time	Memory
281713		MrDomino	Combo (IOI18_combo)	C++14	30 / 100	55 ms	544 KiB

combo

#include <bits/stdc++.h>
#include "combo.h"

using namespace std;

string del(string s, char ch) {
  string t;
  for (auto &x : s) {
    if (x != ch) {
      t += x;
    }
  }
  return t;
}


mt19937 rng((long long) (new char));

string guess_sequence(int n) {
  string sol;
  string posi = "ABXY";
  if (press(sol + posi[0] + posi[1]) > 0) {
    if (press(sol + posi[0])) {
      sol += posi[0];
    } else {
      sol += posi[1];
    }
  } else {
    if (press(sol + posi[2])) {
      sol += posi[2];
    } else {
      sol += posi[3];
    }
  }
  posi = del(posi, sol[0]);
  while ((int) sol.size() < n) {
    bool found = 0;
    shuffle(posi.begin(), posi.end(), rng);
    for (int j = 0; j < 2; j++) {
      if (press(sol + posi[j]) == (int) sol.size() + 1) {
        found = 1;
        sol += posi[j];
        break;
      }
    }
    if (found == 0) {
      sol += posi[2];
    }
  }
  return sol;
}

• Subtask 1: 5 / 5
• Subtask 2: 25 / 95