#include <iostream>

    #include <string>

    bool Find(std::string input, const std::string &substring)

    {

            // If the substring length is bigger than input length, what's the point to continue?

            if (substring.length() > input.length())

                    return false;

            // If both arguments are equal, what's the point to continue?

            if (input == substring)

                    return true;

            int substr_length = substring.length(); // Find 'substring' length

            unsigned int index = 0;

            while (index < input.length())

            {

                    std::string to_compare = "";

                    int f_pos = input.find(substring[0]); // Position in 'input' of the first 'substring' character

                    if (f_pos == input.npos) // Couldn't find?

                            return false;

                    for (int i = f_pos; i <= substr_length + f_pos - 1; i++)

                            to_compare += input[i]; // Build a substring

                    // Compare it with the 'substring' parameter

                    if (to_compare != substring)

                    {

                            int find = input.find(substring[0]); // Position in 'input' of the first 'substring' character

                            if (find != input.npos)

                                    input.erase(find, substr_length - 1); // Erase the substring if it wasn't equal with 'substring'

                    }

                    else

                            return true;

                    index++;

            }

            // To avoid a warning

            return false;

    }

    int main()

    {

            // A simple test:

            if (Find("alex", "lex"))

                    std::cout << "Found substring!" << std::endl;

            else

                    std::cout << "Didn't find substring!" << std::endl;

            return 0;

    }