Submission #1142556

#	Time	Username	Problem	Language	Result	Execution time	Memory
1142556		vyaduct	Combo (IOI18_combo)	C++20	100 / 100	8 ms	596 KiB

combo

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

string guess_sequence(int N) {
  // Guessing first letter
  set<string> S;
  S.insert("A"), S.insert("B"), S.insert("X"), S.insert("Y");

  string p = "";
  int ans = press("AB");
  if (ans >= 1){
    ans = press("A");
    if (ans == 1) p = "A"; 
    else p = "B";
  } else {
    ans = press("X");
    if (ans == 1) p = "X";
    else p = "Y";
  }
  if (N == 1) return p;
  S.erase(p);
  
  int c=0;
  string B, X, Y;
  for (auto x: S){
    if (c == 0) B = x;
    if (c == 1) X = x;
    if (c == 2) Y = x;
    c++;
  }

  // Guessing the other letters
  int cnt=1;
  for (int i=1;i<N-1;i++){
    string trash = (p + B) + (p + X + Y) + (p + X + X) + (p + X + B);
    ans = press(trash);
    if (ans == cnt+1) p += B;
    else if (ans == cnt+2)  p += X;
    else p += Y;
    cnt++;
  }

  // Guessing last letter

  ans = press(p + B + p + X);
  if (ans == N){
    ans = press(p+X);
    if (ans == N) p += X;
    else p += B;
  } else {
    p += Y;
  }
  return p;
}

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