Problem 1856. Molecule Atomic Wt (CHONS) Molecules

Given a molecular equation string determine its atomic weight.

Limited atoms of C H O N and S where wts are rounded to [12 1 16 14 32].

Example molecules and wts:

CH4 16; CH3OH 32; O2 32; C6H6 78; H2SO4 98; radical SO4 96;

Input: Molecular Eqn [string with no spaces, all Caps]

Output: Molecular Wt [approx wt]

Source:

Saw this as a question on Matlab Answers.

Solve

Last solution submitted on Apr 14, 2019

Richard Zapor on 4 Sep 2013

Solution 14 is classic Tim utilizing a multidimensional single for loop with a stunning magical rune string.

Richard Zapor on 2 Sep 2013

Another astounding solution by Alfonso. A symbolic solution with regexprep using an expert logical twist to accommodate all molecules.