Submission #840872

#	Time	Username	Problem	Language	Result	Execution time	Memory
840872		ach00	Combo (IOI18_combo)	C++17	100 / 100	29 ms	672 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
string ans; int n; char first; char one; char two; char remain; string t1,t2,t3;
char next() {
  int val = press((ans + one) + (ans + t1) + (ans + t2) + (ans + t3));
  if(val == (int)ans.size()) {
    return remain;
  } else if(val == (int)ans.size() + 1) {
    return one;
  } else {
    return two;
  }
}
string guess_sequence(int N) {
  n = N;
  if(press("AB")) {
    if(press("A")) {
      first = 'A';
      one = 'B';
      two = 'X';
      remain = 'Y';
      t1 = "XB";
      t2 = "XY";
      t3 = "XX";
    } else {
      first = 'B';
      one = 'A';
      two = 'X';
      remain = 'Y';
      t1 = "XA";
      t2 = "XY";
      t3 = "XX";
    }
  } else {
    if(press("X")) {
      first = 'X';
      one = 'A';
      two = 'B';
      remain = 'Y';
      t1 = "BA";
      t2 = "BY";
      t3 = "BB";
    } else {
      first = 'Y';
      one = 'A';
      two = 'B';
      remain = 'X';
      t1 = "BA";
      t2 = "BX";
      t3 = "BB";
    }
  }
  ans += first;
  if(N==1) return ans;
  while((int)ans.size() < N-1) {
    ans += next();
  }
  if(press((ans+one)+(ans+two)) == N) {
    if(press(ans+one) == N) {
      ans += one;
    } else {
      ans += two;
    }
  } else {
    ans += remain;
  }
  return ans;
}

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