플리나를 위하여

int Problem014(const int scope)
{
	int* numArr = new int[scope + 1];
	for (int i = 0; i <= scope; i++)
	{
		numArr[i] = 0;
	}
	int ret = -1;
	int max = -1;
	for (int i = 2; i <= scope; i++)
	{
		int count = getCollatz(i, numArr, scope);
		if (max < count)
		{
			ret = i;
			max = count;
		}
	}
	delete[] numArr;
	return ret;
}

int getCollatz(long long int number, int*& numArr, const int& scope)
{
	int ret = 1;
	if (number == 1)
	{
		return ret;
	}

	if (number <= scope && numArr[number] > 0)
	{
		ret += numArr[number];
	}
	else
	{
		switch (number % 2)
		{
		case 0:
			ret += getCollatz(number / 2, numArr, scope);
			break;
		case 1:
			ret += getCollatz(3 * number + 1, numArr, scope);
			break;
		default:
			return -1;
		}
	}
	if (number <= scope)
	{
		numArr[number] = ret;
	}
	return ret;
}