#include <iostream>
    #include <string>
    /**
    * return the last n characters of a string,
    * unless n >= length of the input or n <= 0, in which case return ""
    */
    std::string lastN(std::string input, int n) {
        int inputSize = input.size();
        return (n > 0 && inputSize > n) ? input.substr(inputSize - n) : "ccc";
    }
 
    int main() 
    {
    	std::string stringToCheck = "0111111";
 
        std::string lastN(stringToCheck, 4);
 
        std::cout << "Whole String (stringToCheck): \n\n";
        std::cout << stringToCheck;
        std::cout << "\n--- \n\n";
 
        std::cout << "Substring (stringToCheck - n Characters \ne.g. if n = 4, indices 0,1,2,3 get removed from the string): \n\n";
        std::cout << lastN;
        std::cout << "\n--- \n\n";
 
        std::string stringArray[] = { "0111123", "0111456", "0111789", "0111101" };
        int length = sizeof(stringArray) / sizeof(stringArray[0]);
 
        std::cout << "Array String items before substrings extraction and iterations indices: \n\n";
        for(int i = 0; i < length; i++)
        {
            std::cout << stringArray[i] << " " << i << " \n";
        }
        std::cout << "--- \n\n";
 
        std::cout << "Array String items after substrings extraction and iterations indices: \n\n";
        std::cout << "Substring (stringArray[i] - n Characters \ne.g. if n = 4, indices 0,1,2,3 get removed from the string): \n\n";
        for(int i = 0; i < length; i++)
        {
            std::string lastN(stringArray[i], 4);
            std::cout << lastN << " " << i << " \n";
        }
        std::cout << "---\n";
 
 
    	return 0;
    }

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