caesar-cipher-1.cpp

/**
 * @file caesar-cipher-1.cpp
 * @author Alexander Khvolis(ExpliuM)
 * @link https://www.hackerrank.com/challenges/caesar-cipher-1/problem?isFullScreen=true
 * @version 0.1
 * @date 2023-02-18
 * 
 * @copyright Copyright (c) 2023
 * 
 */

#include <functional>
#include <iostream>
#include <sstream>
#include <fstream>
#include <string>
#include <vector>

using namespace std;

string ltrim(const string &);
string rtrim(const string &);

/*
 * Complete the 'caesarCipher' function below.
 *
 * The function is expected to return a STRING.
 * The function accepts following parameters:
 *  1. STRING s
 *  2. INTEGER k
 */

string caesarCipher(string s, int k)
{
    int shiftFactor = k % 26;
    int length = s.size();

    char cstr[length + 1];
    std::copy(s.begin(), s.end(), cstr);
    cstr[length] = '\0';

    for (int index = 0; index < length; ++index)
    {
        if (isalpha(cstr[index]))
        {
            cstr[index] += shiftFactor;

            if (isalpha(cstr[index]) == 0 || isupper(cstr[index]) != isupper(s[index]))
            {
                cstr[index] -= 26;
            }
        }
    }

    return cstr;
}

int main()
{
    // ofstream fout(getenv("OUTPUT_PATH"));

    string n_temp;
    getline(cin, n_temp);

    int n = stoi(ltrim(rtrim(n_temp)));

    string s;
    getline(cin, s);

    string k_temp;
    getline(cin, k_temp);

    int k = stoi(ltrim(rtrim(k_temp)));

    string result = caesarCipher(s, k);

    cout << result << "\n";
    // fout << result << "\n";

    // fout.close();

    return 0;
}

string ltrim(const string &str)
{
    string s(str);

    s.erase(
        s.begin(),
        find_if(s.begin(), s.end(), not1(ptr_fun<int, int>(isspace))));

    return s;
}

string rtrim(const string &str)
{
    string s(str);

    s.erase(
        find_if(s.rbegin(), s.rend(), not1(ptr_fun<int, int>(isspace))).base(),
        s.end());

    return s;
}