Submission #647637

#	Time	Username	Problem	Language	Result	Execution time	Memory
647637		Truitadepatates	Combo (IOI18_combo)	C++14	100 / 100	43 ms	596 KiB

combo

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

const int M = 4;
const char A[] = "ABXY";

int guess_one(const string& s) {
  int len = press(s + A[0] + s + A[1]);
  int idx = 2*(len < s.length()+1);
  len = press(s + A[idx]);
  idx += (len < s.length()+1);
  return idx;
}

string guess_sequence(int N) {
  int idx[M];
  for (int i = 0; i < M; i++) { 
    idx[i] = i;
  }
  string s;
  int id = guess_one(s);
  s += A[id];
  swap(idx[id], idx[M-1]);
  
  for (int i = 0; i < N-2; i++) {
    string z;
    for (int j = 0; j < M-1; j++) {
      z += s + A[idx[0]] + A[idx[j]];
    }
    z += s + A[idx[1]];
    int len = press(z);
    if (len == i+3) {
      s += A[idx[0]];
    } else if (len == i+2) {
      s += A[idx[1]];
    } else {
      s += A[idx[2]];
    }
  }

  if (N > 1) {
    int id = guess_one(s);
    s += A[id];
  }

  return s;
}

Compilation message (stderr)

combo.cpp: In function 'int guess_one(const string&)':
combo.cpp:10:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |   int idx = 2*(len < s.length()+1);
      |                ~~~~^~~~~~~~~~~~~~
combo.cpp:12:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |   idx += (len < s.length()+1);
      |           ~~~~^~~~~~~~~~~~~~

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