#include <iostream>
#include <vector>
#include <string>

int main()
{
    std::string input = " know me? do you ";

    int count = 0;

    //
    // get words
    //

    std::vector<std::string> words;
    std::string word;

    size_t length = input.length();

    for (size_t i = 0; i < length; ++i)
    {
        if (input[i] != ' ' && i != length - 1)
        {
            word += input[i];
        }
        else
        {
            if (word.length() > 0)
            {
                words.push_back(word);
                word.clear();
                count++;
            }
        }
    }

    //
    // print words
    //

    std::cout << count << std::endl;

    for (std::vector<std::string>::iterator it = words.begin(); it != words.end(); it++)
    {
        std::cout << *it << std::endl;
    }

    std::cout << "===" << std::endl;

    //
    // permutate vector
    //

    int firstWord = 2;
    int lastWord = 3;

    int repeat = 0;

    while (repeat < lastWord - firstWord + 1)
    {
        for (int i = lastWord; i > 0; i--)
        {
            std::swap(words[i], words[i - 1]);
        }

        repeat++;
    }

    //
    // print permutated vector
    //

    for (std::vector<std::string>::iterator it = words.begin(); it != words.end(); it++)
    {
        std::cout << *it << std::endl;
    }

    //
    // build & print new string
    //

    std::string result;

    for (std::vector<std::string>::iterator it = words.begin(); it != words.end(); it++)
    {
        if (it != words.begin())
        {
            result += ' ';
        }

        result += *it;
    }

    std::cout << "result: " << result << std::endl;

    return 0;
}