Submission #843999

#	Time	Username	Problem	Language	Result	Execution time	Memory
843999		Dat160601	Combo (IOI18_combo)	C++17	100 / 100	13 ms	2012 KiB

combo

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

#define mp make_pair
#define pb push_back
#define fi first
#define se second

string guess_sequence(int N) {
  string ans = "";
  char arr[4] = {'A', 'B', 'X', 'Y'};
  vector<char> listPos;
  if(press("AB") >= 1) {
    if(press("A") == 1) {
      ans = "A";
    }
    else {
      ans = "B";
    }
  }
  else {
    if(press("X") == 1) {
      ans = "X";
    }
    else {
      ans = "Y";
    }
  }
  if(N == 1) return ans;

  for(int i = 0; i < 4; i++) {
    if(arr[i] != ans[0]) listPos.pb(arr[i]);
  }

  for(int i = 2; i < N; i++) {
    string query = ans + listPos[0];
    query += ans + listPos[1] + listPos[0];
    query += ans + listPos[1] + listPos[1];
    query += ans + listPos[1] + listPos[2];
    int res = press(query);
    if(res == i - 1) ans += listPos[2];
    else if(res == i) ans += listPos[0];
    else ans += listPos[1];
  }

  int cnt = 0;
  for(int i = 0; i < 3; i++) {
    cnt++;
    if(cnt == 3 || press(ans + listPos[i]) == N) {
      ans += listPos[i];
      return ans;
    }
  }
  return ans;
}

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