s2num.cpp

// uses algos from https://benkurtovic.com/2014/06/01/obfuscating-hello-world.html
#include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <gmpxx.h>

template<typename Type>
void pv(const std::string name, const std::vector<Type>& vec)
{
	size_t i;
	std::cout << name << " = {" << std::flush;
	for(i=0; i<vec.size(); i++)
	{
		std::cout << vec[i];
		if((i+1) != vec.size())
		{
			std::cout << ", ";
		}
		std::cout << std::flush;
	}
	std::cout << "};" << std::endl;
}

mpz_class s2num(const std::string& str)
{
	size_t i;
	mpz_class sum;
	std::vector<int> codes;
	std::vector<mpz_class> temp;
	sum = 0;
	for(i=0; i<str.size(); i++)
	{
		codes.push_back(str[i]);
	}
	for(i=0; i<codes.size(); i++)
	{
		temp.push_back(codes[i] * std::pow(256, i));
	}
	for(auto& n: temp)
	{
		sum += n;
	}
	pv("codes", codes);
	pv("temp", temp);
	return sum;
}

std::string num2s(const mpz_class& num)
{
	if(num > 0)
	{
		return (char(num.get_ui() % 256) + num2s(num / 256));
	}
	return "";
}

int main()
{
	std::string s = "Hello World!";
	auto a = s2num(s);
	auto b = num2s(a);
	std::cout << "a = " << a << std::endl;
	std::cout << "b = " << b << std::endl;
}