void invInterpol(std::vector<double> knotsX, std::vector<double> knotsY, double &x)
{
    int n = knotsX.size();
    std::vector<std::vector<double> > diffs;
    
    std::vector<double> temp;
    for (int i = 0; i < n-1; ++i)
    {
        temp.push_back((knotsY[i] - knotsY[i+1]) / (knotsX[i] - knotsX[i + 1]));
    }
    diffs.push_back(temp);
    n = temp.size();
    temp.clear();
    
    for (int i = 1, count = 2; i < knotsX.size() - 1; ++i, count++)
    {
        for (int j = 0; j < n-1; j++)
        {
            temp.push_back((diffs[i - 1][j+1] - diffs[i - 1][j]) / (knotsX[j+count] - knotsX[j]));
        }
        diffs.push_back(temp);
        n = temp.size();
        temp.clear();
    }

    x = knotsX[0];
    double norm;

    do
    {
        double t = knotsY[0];
        int count = 2;
        for (int i = 1; i < diffs.size(); ++i)
        {
            double prod = 1;
            for (int j = 0; j < count; ++j)
            {
                prod *= (x - knotsX[j]);
            }
            t += diffs[i][0] * prod;
            count++;
        }
        double xNext = knotsX[0] - t / diffs[0][0];
        norm = fabs(xNext - x);
        x = xNext;
    } while (norm > 1e-5);
}