double gauss(double tab[][SIZE], double b[SIZE]) {
	double arr[SIZE][SIZE], D[SIZE], b2[SIZE], x2[SIZE], x1[SIZE] = { 1.,1.,1.,1. };
	int n = 0;
	for (int i = 0; i < SIZE; i++)
	{
		for (int j = 0; j < SIZE; j++)
		{
			arr[i][j] = tab[i][j];
		}
	}
	//algroyytm
	for (int k = 0; k < nmax; k++)
	{
		for (int i = 0; i < SIZE; i++)
		{
			x2[i] = b[i];
			for (int j = 0; j < SIZE; j++)
			{
				x2[i] += arr[i][j] * x1[j];
			}
			x2[i] = x2[i] / arr[i][i];
		}
		for (int i = 0; i < SIZE; i++)
		{
			std::cout << x2[i] << " ";
		}
	}
	return 0;
}