Submission #1117344

#	Time	Username	Problem	Language	Result	Execution time	Memory
1117344		Unconcurrent	Password (RMI18_password)	C++17	0 / 100	8 ms	592 KiB

password

// (C) Sologub Radu
#include <iostream>
#include <cmath>
#include <vector>
#include <fstream>
#include <algorithm>
#include <iomanip> // for std::setw and std::setfill
#include <map>
#include <chrono>

using namespace std;

const bool fileInput = false;
istream& input = *(fileInput ? new fstream("./input.in") : &cin);


// https://rmi.lbi.ro/rmi_2018/aj password

// Mock password for testing purposes
string actualPassword = "aaa";


int longestPrefixSubsequenceLength(const std::string& input1, const std::string& input2) {
    int len1 = input1.length();
    int len2 = input2.length();

    // Two pointers to keep track of the characters in both strings
    int i = 0; // Pointer for input1 (prefix)
    int j = 0; // Pointer for input2 (source for subsequence)

    // Iterate over the characters in both strings
    while (i < len1 && j < len2) {
        // If the characters match, move the pointer in input1
        if (input1[i] == input2[j]) {
            i++;
        }
        // Always move the pointer in input2
        j++;
    }

    // The value of i gives us the length of the longest prefix
    return i;
}

int query( string str) ;
string guess(int len, int alphabet){
    string guess = "a";
    // first char guess
    while(query(guess) != 1){
        guess[0]++;
    }

    forward_looking:
    // forward looking
    char forwardGuess = 'a';
    while(query(guess + forwardGuess) < guess.size() + 1 && forwardGuess < 'a' + alphabet){
        forwardGuess++;
    }

    if(forwardGuess >= 'a' + alphabet){
        // failed forward look, skip;
    }else{
        // success
        guess = guess + forwardGuess;
        // cout << guess << endl;
        goto forward_looking;
    }


    int backInsertIndex = guess.size() - 1;
    back_inserter:
    if(guess.size() == len){
        return guess;
    }
    
    string backGuess = "a";
    backGuess[0]--;
    
    string guessTry;
    do{
        guessTry = guess;
        backGuess[0]++;
        guessTry.insert(backInsertIndex, backGuess);
        // cout << "guessTry = " << guessTry << endl;
    }while(backGuess[0] < 'a' + alphabet
        && query(guessTry) < guess.size() + 1);
    
    if(backGuess[0] >= 'a' + alphabet){
        // failed back insert at index;
        backInsertIndex --;
        if(backInsertIndex < 0){
            backInsertIndex = guess.size() - 1;
        }
    }else{
        // success
        // backInsertIndex --;
        guess = guess.insert(backInsertIndex, backGuess);
        // cout << guess << endl;
    }
    goto back_inserter;
}

Compilation message (stderr)

password.cpp: In function 'std::string guess(int, int)':
password.cpp:56:39: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |     while(query(guess + forwardGuess) < guess.size() + 1 && forwardGuess < 'a' + alphabet){
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
password.cpp:72:21: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   72 |     if(guess.size() == len){
      |        ~~~~~~~~~~~~~^~~~~~
password.cpp:86:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   86 |         && query(guessTry) < guess.size() + 1);
      |            ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~

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