Upon close study of their article, we realized that the distribution of stable oxidation products can be solved exactly, without the greedy heuristic. Twyman et al. note that their problem has the form of a continuous (or fractional) knapsack problem. Indeed, integer knapsack problems are NP-complete, and smaller problems are typically solved through dynamic programming, whereas larger problems require the use of heuristics. However, continuous knapsack problems have a straightforward and exact solution in terms of a linear optimization problem (also known as linear programming, LP). Essentially, one solves for a vector of products minimizing the total formation enthalpy, subject to a set of stoichiometric constraints.