4. Letters

#include <iostream>
#include <string>
#include <sstream>
#include <vector>
#include <queue>
#include <set>

using namespace std;

vector<string> readInput()
{
    vector<string> result;
    string text;
    getline(cin, text);
    istringstream input(text);

    string word;

    while (input >> word)
    {
        result.push_back(word);
    }

    return result;
}

queue<char> readLetters()
{
    queue<char> result;
    char letter;
    cin >> letter;
    while (letter != '.')
    {
        result.push(letter);
        cin >> letter;
    }
    return result;
}

void clearWord(string &currWord)
{
    if (ispunct(currWord.back()))
    {
        currWord.pop_back();
    }

    if (ispunct(currWord.front()))
    {
        currWord.erase(currWord.begin());
    }
}

void findLetter(string & word, const char &letter, set<string>& temp)
{
    clearWord(word);

    const int size = word.size();
    for (int i = 0; i < size; i++)
    {
        if (word[i] == letter || word[i] == (letter - 32) || word[i] == (letter + 32))
        {
            temp.insert(word);
        }
    }
}

void findMatchedWords(vector<string> &inputText,
                            queue<char>& letters)
{
    const int sizeOfVector = inputText.size();

    while (!letters.empty())
    {
        set<string> matchedWord;
        for (int i = 0; i < sizeOfVector; i++)
        {
            findLetter(inputText[i], letters.front(), matchedWord);
        }
        if (matchedWord.size() > 0)
        {
            for (string elem : matchedWord)
            {
                cout << elem << ' ';
            }
        }
        else
        {
            cout << "---";
        }
        cout << endl;
        letters.pop();
    }
}

int main()
{
    vector<string> text = readInput();
    queue<char> searchedLetters = readLetters();

    findMatchedWords(text, searchedLetters);

    return 0;
}