Submission #918606

#	Time	Username	Problem	Language	Result	Execution time	Memory
918606		AtabayRajabli	Password (RMI18_password)	C++17	Compilation error	0 ms	0 KiB

password

// Sample grader for contestants' use.
//
// Usage: place your input data in the file password.in in the format
//
// line 1: N S
// line 2: hidden_password
//
// Then compile this grader together with your implementation.
// Run the binary to see your guessing strategy at work!
// Set DEBUG to 1 to print all queries.
#include <fstream>
#include <iostream>
#include <sstream>
#include <string>
#include <stdlib.h>
#include <assert.h>

using namespace std;

#define DEBUG 0
#define MAX_QUERIES 50000
#define MAX_N 5000
#define MAX_SIGMA 26

static string password;
static int n, s, numQueries;
static stringstream msg;

static void end(int success) {
  cout << (success ? "SUCCESS! " : "ERROR: ") << msg.str() << endl;
  exit(0);
}

int query(string q) {
  if (++numQueries > MAX_QUERIES) {
    msg << "Could not guess the password with " << MAX_QUERIES << " questions.";
    end(0);
  }

  int len = q.size();

  // validation
  if (len < 1 || len > n) {
    msg << "Query '" << q << "' should have length between 1 and "
        << n << " characters.";
    end(0);
  }

  for (int i = 0; i < len; i++) {
    if (q[i] < 'a' || q[i] >= 'a' + s) {
      msg << "Illegal character '" << q[i] << "' found.";
      end(0);
    }
  }

  // while possible, advance one character in q and find its next
  // occurrence in password
  int i = 0, j = 0, plen = password.size();
  while (i < plen && j < len) {
    while ((i < plen) && (password[i] != q[j])) {
      i++;
    }
    if (i < plen) { /* found a match */
      i++;
      j++;
    }
  }

  if (DEBUG) {
    cout << "Question #" << numQueries << " [" << q << "] answer " << j << endl;
  }
  return j;
}

string guess(int n, int s)
{
  int comb[26][26] = {0};
  int freq[26] = {0};

  for(int i = 0; i < 26; i++)
  {
    int l = 0, r = n;
    while(l <= r)
    {
      int mid = (l + r) / 2;
      string x = "";
      for(int j = 0; j < mid; j++)x.push_back(char(i + 'a'));

      if(query(x) < n)l = mid + 1;
      else r = mid - 1;
    }
    freq[i] = r + 1;
  }

  string ans = "";
  for(int i = 0; i < s; i++)
  {
    int ok = 1;
    for(int j = 0; j < s; j++)
    {
      string x = "";
      x.push_back(char(i +'a'));
      int cnt = freq[j];
      while(cnt--)x.push_back(char(j + 'a'));

      comb[i][j] = x.size();
    }
  }

  for(int ind = 0; ind < n; ind++)
  {
    for(int i = 0; i < 26; i++)
    {
      bool check = 1;
      for(int j = 0; j < 26; j++)
      {
        if(comb[i][j] != freq[j] + 1)
        {
          check = 0;
          break;
        }
      }
      if(check)
      {
        ans += char(i + 'a');
        freq[i]--;
        break;
      }
    }
  }

    return ans;
}

int main() {

  ifstream f("password.in");
  f >> n >> s >> password;
  f.close();
  assert(n && s && !password.empty());

  string answer = guess(n, s);
  if (DEBUG) {
    cout << "Your answer: [" << answer << "]\n";
  }

  if (answer.compare(password)) {
    msg << "Your answer was [" << answer
        << "] which does not match the password [" << password << "].";
    end(0);
  } else {
    msg << "You guessed the password with " << numQueries << " queries.";
    end(1);
  }

	return 0;
}

Compilation message (stderr)

password.cpp: In function 'std::string guess(int, int)':
password.cpp:98:9: warning: unused variable 'ok' [-Wunused-variable]
   98 |     int ok = 1;
      |         ^~
/usr/bin/ld: /tmp/ccDsEFrM.o: in function `query(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)':
grader.cpp:(.text+0x80): multiple definition of `query(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)'; /tmp/ccRTsdhN.o:password.cpp:(.text+0x1b0): first defined here
/usr/bin/ld: /tmp/ccDsEFrM.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccRTsdhN.o:password.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status