Project Euler #56

euler.cpp

#include <string>
#include <iostream>
#include <sstream>
#include <algorithm>

class Hugenum
{
	public:
	std::string str; //stores the number in decimal form, this is a horrible way to store numbers, but it works for almost any size we can imagine

	Hugenum(int initial);
	void add(Hugenum operand);
	int digitcount();
};

Hugenum::Hugenum(int initial)
{
//	std::iostream = std::stringstream(str) << initial;
	std::stringstream ss;
	ss<<initial;
	str=ss.str();
	std::reverse(str.begin(), str.end());
} 

//operand must not be bigger than the current value
void Hugenum::add(Hugenum operand)
{
	int carry=0;
	size_t i;

	if(operand.str.length() > str.length())
	{
		std::cout << "You've done someting horribly wrong" << std::endl;
		exit(EXIT_SUCCESS);
	}

	for(i=0;i<operand.str.length(); i++)
	{
		int a = str[i]-'0';
		int b = operand.str[i] -'0';

		int result= a+b+carry;

		carry=result/10;
		result=result%10;

		str[i]='0'+result;
	}
	//This doesn't work...
	
	while(carry!=0)
	{
		if(i<str.length())
		{
			int a = str[i]-'0';
			int result=a+carry;

			carry=result/10;
			result=result%10;

			str[i]='0'+result;
			i++;
		}
		else
		{
			str+= '0'+carry;
			carry=0;
		}
	}
}

int Hugenum::digitcount()
{
	int ret=0;
	for(size_t i=0; i< str.length(); i++)
	{
		ret+=str[i]-'0';
	}
	return ret;
}


int main()
{
	int max=0;
	for(int i=1; i<=100;i++)
	{
		Hugenum a(i);
		for(int j=1; j<=100; j++)
		{
			//Calculate i^j
			Hugenum b=a;
			
			for(int k=1; k<i; k++)
			{
				a.add(b);
			}

			if(a.digitcount()>max)
			{
				max=a.digitcount();
			}
		}
	}
	std::cout << max <<std::endl;

	return 0;
}