제출 #1142562

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1142562		qwerty13579	Combo (IOI18_combo)	C++20	0 / 100	0 ms	408 KiB

combo

#include "bits/stdc++.h"
#include "combo.h"

using namespace std;

std::string guess_sequence(int n) {
  string pb = "ABXY";
  string possibilities = "";
  string p = "";
  string s = "";

  if (press("AB") > 0){ // if AB is 1
    if (press("A") == 1) p += 'A'; // if A is 1 add to s A
    else p += 'B'; // else add to s B
  } else if (press("X") == 1) p += 'X'; // if X is 1 add to s X
  else p+='Y'; // else add Y

  s=p; // add to p the prefix found

  for (int i=0;i<pb.size();++i){
    if (pb[i]==s[0]) continue;
    possibilities+=pb[i]; // remove the prefix from the possibilities
  }

  // generate the string to ask until press(p) == n
  // p and add to p the first character in possibilities that's not the prefix, then add the second one and append to the second one all other three that's not the prefix
  int last_ans = 1;
  while(true)
  {
    if (p.size()==n-1){
      break;
    }
    string toAdd = ""; // str to add to not modify p yet

    toAdd+=possibilities[0]; // add first character
    toAdd+=s[0]; // add prefix
    toAdd+=possibilities[1]; // add second character

    // to second character add all the possibilities
    for(int i=0;i<possibilities.size();++i){
      toAdd+=possibilities[i];
      if (i<possibilities.size()-1){
        toAdd+=s[0];
        toAdd+=possibilities[1];
      }
    }
    // ask
    int ans = press(p + toAdd);
    // if we get 1, the sole character is good
    if (ans-last_ans==1){
      p+=possibilities[0];
    } else if (ans-last_ans > 1){ // else if we get 2 the second character is good
      p+=possibilities[1];
    } else { // else it's the one we didn't ask of
      p+=possibilities[2];
    }
    // update last ans;
    last_ans = ans;
  }

  if(press(p + possibilities[0]) - last_ans == 1) p+=possibilities[0];
  else if(press(p + possibilities[1]) - last_ans == 1) p+=possibilities[1];
  else p+=possibilities[2];

  s=p;
  
  return s;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 95