Submission #131978

#	Time	Username	Problem	Language	Result	Execution time	Memory
131978		dvdg6566	Combo (IOI18_combo)	C++14	5 / 100	2 ms	456 KiB

combo

#include "combo.h"
#include<bits/stdc++.h>
using namespace std;
#define pb emplace_back
#define mp make_pair
#define ALL(x) x.begin(), x.end()
#define SZ(x) (int)x.size()

char ltrs[] = {'A', 'B', 'X', 'Y'};

string guess_sequence(int N) {
  // cout<<N<<'\n';
  string out="";
  int a = press("AB");
  int b = press("AX");
  if(a&&b)out+='A';
  if (a&&!b)out+='B';
  if (!a&&b)out+='X';
  if(!a&&!b)out+='Y';
  vector<char> V;
  for (int i=0;i<4;++i)if(ltrs[i] != out[0])V.pb(ltrs[i]);

  for (int x=2;x<N;++x){
    string q = "";
    for (auto i : out)q+=i;
    q += V[0];
    q += V[0];
    for (auto i : out)q+=i;
    q += V[0];
    q += V[1];
    for (auto i : out)q+=i;
    q += V[0];
    q += V[2];
    for (auto i : out)q+=i;
    q += V[1];
    // cout<<q<<'\n';
    int res = press(q);
    // cout<<res<<' '<<x<<'\n';
    if (res == x-1){
      out += V[2];
    }else if (res == x+1){
      out += V[0];
    }else{
      out += V[1];
    }
    assert(SZ(out)== x);
  }
  assert(SZ(out)==N-1);
  out += V[0];
  if (press(out) == N)return out;
  out.pop_back();
  out += V[1];
  if (press(out) == N)return out;
  out.pop_back();
  out += V[2];
  return out;
}

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