Submission #858020

#	Time	Username	Problem	Language	Result	Execution time	Memory
858020		Pety	Password (RMI18_password)	C++14	50 / 100	311 ms	1196 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>
#include <vector>

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) { 
//       i++;
//       j++;
//     }
//   }

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

int query(string s);

int fr[26];

string guess (int n, int s) {
  for (char c = 'a'; c < 'a' + s; c++) {
    string s;
    for (int i = 0; i < n; i++)
      s += c;
    fr[c - 'a'] = query(s);
  }
  string a;
  for (int i = 0; i < fr[0]; i++)
    a += 'a';
  for (int i = 1; i < s; i++) {
    string b;
    for (int j = 0; j < fr[i]; j++)
      b += 'a' + i;
    string cp;
    cp = a;
    vector<int>p(a.size()+2);
    int t = a.size();
    int last = 0;
    for (int j = 0; j <= t; j++) {
      int x = query(a + b);
      p[t - j] = x - a.size() - last;
      last += p[t - j];
      if (a.size())
        a.pop_back();
    }
    a = cp;
    b = "";
    for (int j = 0; j <= a.size(); j++) {
      for (int k = 0; k < p[j]; k++)
        b += 'a' + i;
      if (j < a.size())
        b += a[j];
    }
    a = b;
  }
  return a;
}

// 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:108:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  108 |     for (int j = 0; j <= a.size(); j++) {
      |                     ~~^~~~~~~~~~~
password.cpp:111:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  111 |       if (j < a.size())
      |           ~~^~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 0 / 30
• Subtask 5: 0 / 20