Submission #89423

#	Time	Username	Problem	Language	Result	Execution time	Memory
89423		Good	Combo (IOI18_combo)	C++11	100 / 100	47 ms	636 KiB

combo

#include "combo.h"
#include <algorithm>

using namespace std;

std::string guess_sequence(int N) {
  /*std::string p = "";
  for (int i = 0; i < 4 * N; ++i) {
    p += 'A';
  }
  int coins = press(p);
  std::string S = "";
  for (int i = 0; i < N; ++i) {
    S += 'A';
  }
  return S;*/


int n = N;
  string s = "";
  string ans = "";
  
  s = "AB";
  int a = press (s);
  
  if (a == 2) ans += 'A'; 
  else if (a == 1) {
    a = press ("A");
    if (a == 1) ans += 'A';
    else ans += 'B';   
  }
  else {
    a = press ("X");
    if (a == 1) ans += 'X';
    else ans += 'Y';    
  } 
  
  char b = ans[0];
  for (int i = 2; i < n; i++) {
    int x = ans.size();
    s = "";
    if (b == 'A') {
      s += ans + "BX", s += ans + "BY",
      s += ans + "BB", s += ans + "X";
    
      a = press (s);
      if (a == x + 2) ans += 'B';
      else if (a == x + 1) ans += 'X';
      else ans += 'Y';  
    }
    
    if (b == 'B') {
      s += ans + "AX", s += ans + "AY",
      s += ans + "AA", s += ans + "X";
      
      a = press (s);
      if (a == x + 2) ans += 'A'; 
      else if (a == x + 1) ans += 'X';
      else ans += 'Y';
    }
    if (b == 'X') {
      s += ans + "BA", s += ans + "BY",
      s += ans + "BB", s += ans + "A";
      
      a = press (s);
      if (a == x + 2) ans += 'B'; 
      else if (a == x + 1) ans += 'A';
      else ans += 'Y';
    }
    if (b == 'Y') {
      s += ans + "BX", s += ans + "BA",
      s += ans + "BB", s += ans + "X";
      
      a = press (s);
      if (a == x + 2) ans += 'B'; 
      else if (a == x + 1) ans += 'X';
      else ans += 'A';
    }
  }
  
  if (n > 1) {
    int x = ans.size();
    s = ans + 'A' + ans + 'B'; 
    a = press (s);
    
    if (a == x + 1) {
      s = ans + 'A';
      a = press (s);
      
      if (a == x + 1)
        ans += 'A';
      else
        ans += 'B'; 
    }
    else {
      s = ans + 'X';
      a = press (s);
      if (a == x + 1)
        ans += 'X';
      else
        ans += 'Y'; 
    }
  } 
  
  return ans;

}

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