Submission #428477

#	Time	Username	Problem	Language	Result	Execution time	Memory
428477		ivan24	Combo (IOI18_combo)	C++14	0 / 100	1 ms	256 KiB

combo

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

using ll = long long int;
typedef vector<ll> vi;
typedef pair<ll,ll> ii;
typedef vector<ii> vii;
typedef vector<vi> vvi;
#define F first
#define S second

ll min(ll x, ll y){
    return ((x < y) ? x : y);
}

ll max(ll x, ll y){
    return ((x > y) ? x : y);
}

/*

namespace {

constexpr int MAX_N = 2000;
constexpr int MAX_NUM_MOVES = 8000;

int N;
std::string S;

int num_moves;

void wrong_answer(const char *MSG) {
  printf("Wrong Answer: %s\n", MSG);
  exit(0);
}

}  // namespace

int press(std::string p) {
  if (++num_moves > MAX_NUM_MOVES) {
    wrong_answer("too many moves");
  }
  int len = p.length();
  if (len > 4 * N) {
    wrong_answer("invalid press");
  }
  for (int i = 0; i < len; ++i) {
    if (p[i] != 'A' && p[i] != 'B' && p[i] != 'X' && p[i] != 'Y') {
      wrong_answer("invalid press");
    }
  }
  int coins = 0;
  for (int i = 0, j = 0; i < len; ++i) {
    if (j < N && S[j] == p[i]) {
      ++j;
    } else if (S[0] == p[i]) {
      j = 1;
    } else {
      j = 0;
    }
    coins = std::max(coins, j);
  }
  return coins;
}

int main() {
  char buffer[MAX_N + 1];
  if (scanf("%s", buffer) != 1) {
    fprintf(stderr, "Error while reading input\n");
    exit(1);
  }
  S = buffer;
  N = S.length();

  num_moves = 0;
  std::string answer = guess_sequence(N);
  if (answer != S) {
    wrong_answer("wrong guess");
    exit(0);
  }
  printf("Accepted: %d\n", num_moves);
  return 0;
}

//*/

class Solver{
private:
    string outp;
    ll n;
    void getFirstChar(){
        ll res = press("AB");
        if (res == 2) outp = "AB";
        else if (res == 1){
            res = press("A");
            if (res == 1) outp = "A";
            else outp = "B";
        }else{
            res = press("C");
            if (res == 1) outp = "C";
            else outp = "D";
        }
    }
public:
    Solver(ll n): n(n){
        getFirstChar();
        vector<char> ogchoices = {'A','B','X','Y'};
        vector<char> choices;
        for (auto c: ogchoices){
            if (c != outp[0]) choices.push_back(c);
        }
        while (outp.size() < n){
            ll startSize = outp.size();
            bool found = false;
            for (ll i = 0; 2 > i; i++){
                string query = outp;
                query.push_back(choices[i]);
                ll res = press(query);
                if (res == query.size()){
                    found = true;
                    outp.push_back(choices[i]);
                    break;
                }
            }
            if (!found){
                outp.push_back(choices[2]);
            }
            assert(startSize+1 == outp.size());
        }
    }
    string solve(){
        return outp;
    }
};

string guess_sequence(int n) {
    Solver solver(n);
    return solver.solve();
}

Compilation message (stderr)

combo.cpp: In constructor 'Solver::Solver(ll)':
combo.cpp:113:28: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
  113 |         while (outp.size() < n){
      |                ~~~~~~~~~~~~^~~
combo.cpp:120:25: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  120 |                 if (res == query.size()){
      |                     ~~~~^~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from combo.cpp:2:
combo.cpp:129:32: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  129 |             assert(startSize+1 == outp.size());
      |                    ~~~~~~~~~~~~^~~~~~~~~~~~~~

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