Submission #1272037

#	Time	Username	Problem	Language	Result	Execution time	Memory
1272037		solstice	Combo (IOI18_combo)	C++20	100 / 100	9 ms	480 KiB

combo

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

// #define int long long

string guess_sequence(int n) {
  string p;
  set<string> st;
  st.insert("A"); st.insert("B");
  st.insert("X"); st.insert("Y");

  int c = press("AB");
  if (c >= 1) {
    c = press("A");
    if (c == 1) p = "A";
    else p = "B";
  } else {
    c = press("X");
    if (c == 1) p = "X";
    else p = "Y";
  }

  if (n == 1) return p;
  string b, x, y;
  c = 0;
  for (auto i : st) {
    if (i == p) continue;
    if (c == 0) b = i;
    else if (c == 1) x = i;
    else y = i;
    ++c;
  }
  int cnt = 1;
  for (int i = 1; i < n - 1; ++i) {
    string t = p + b + p + x + y + p + x + x + p + x + b;
    c = press(t);
    if (c == cnt) p += y;
    else if (c == cnt + 1) p += b;
    else p += x; 
    cnt++;
  }
  c = press(p + b);
  if (c == n) {
    p += b;
  }
  else {
    c = press(p + x);
    if (c == n) p += x;
    else p += y;
  }
  return p;
}

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