CSMSL.Chemistry.ChemicalFormulaGenerator.GenerateFormulaHelper C# (CSharp) Method

        private static void GenerateFormulaHelper(double lowMass, double highMass, double[] masses, int[] max, int index, int[] currentFormula, List<ChemicalFormula> formulas)
        {
            while (index > 0 && max[index] == 0)
            {
                index--;
            }
            if (index > 0)
            {
                int maxCount = Math.Min((int) Math.Ceiling(highMass/masses[index]), max[index]);
                for (int count = 0; count <= maxCount; count++)
                {
                    currentFormula[index] = count;
                    GenerateFormulaHelper(lowMass, highMass, masses, max, index - 1, currentFormula, formulas);
                }
            }
            else
            {
                double massAtIndex = masses[index];
                currentFormula[index] = 0;
                double currentMass = currentFormula.Zip(masses, (i, m) => i*m).Sum();
                int minCount = Math.Max((int) Math.Floor((lowMass - currentMass)/massAtIndex), 0);
                int value = (int) Math.Ceiling((highMass - currentMass)/massAtIndex);
                int maxCount = Math.Min(value, max[index]);
                for (int count = minCount; count <= maxCount; count++)
                {
                    currentMass += count*massAtIndex;
                    currentFormula[index] = count;

                    if (currentMass >= lowMass && currentMass <= highMass)
                    {
                        ChemicalFormula formula = new ChemicalFormula(currentFormula);
                        if (!formula.MassEquals(0.0))
                            formulas.Add(formula);
                    }
                    currentMass -= count*massAtIndex;
                }
            }
        }