CPalindrome.h

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

class CPalindrome
{
private:
//functions which counts appearances of letters and store that data in a map or a vector
    static void count_letters(const std::string &s, std::vector<int> &chars);
    static void count_letters(const std::string &s, std::map<char, int> &chars);

//functions that count how many letters appear odd number of times
    static size_t count_odds(std::vector<int> &chars);
    static size_t count_odds(std::map<char, int> &chars);

//function that counts the difference between char a and char b
    static int difference(char a, char b);

public:
    CPalindrome();
    ~CPalindrome();

//checks correctness of provided string
    static bool if_correct(const std::string &s);

//checks if given string is a palindrome
    static bool if_palindrome(const std::string &s);

//returns minimum number of changes that are needed to change the given string into a palidrome (possible only increasing or decreasing of letters)
    static int to_palindrome(const std::string &s);

//returns minimum number of changes that are needed to change the given string into a near-palidrome (possible only increasing or decreasing of letters)
    static int to_near_palindrome(std::string &s);
    
//checks if there can be a removal of one letter to change the given string into a palidrome
    static bool if_one_sign_away(const std::string &s);

//checks if there can be a removal of one letter to change the given string into a near-palidrome
    static bool if_one_sign_away_from_np(const std::string &s);
    
//rearranges letters in given string to make a lowest palindrome, if it is not possible return "None"
    static std::string find_palindrome(std::string &s);
    
//finds the longest palidrome in given string, if there is none return "None"
    static std::string longest_palindrome(std::string &s);
    
//returns the smallest alphabetically string that is a near palindrome, doing as few operations as possible (possible is only changing of letter into a different one)
    static int even_palindrome(std::string &s);

//checks if given integer is a palindrome
    static bool int_is_palindrome(const int &i);
};