Develop a sorting algorithm for molecular formulas

[smenjas]

The sorting algorithm must work for empirical and molecular formulas. Condensed formulas are not required for the first iteration.

For organic compounds, the pattern begins with carbon, then often lists other elements in order of atomic number. For example, CO2 would come before CF2.

[smenjas]

Formula sort has 2 bugs. It doesn't work when:

• only one formula contains the priority element,
• one formula has only the priority element, and no others.