Write a C++ program to predict the molecular geometry of molecules based on formulas like AB_b, where the approximate shape is one A atom in the centre surrounded by b B atoms. The Valence-Shell Electron-Pair Repulsion Model (VSEPR model) is commonly used for this task and consists of these four steps: 1. set v for the centre atom A using a nested-if and the information in Table 1 2. e = v - b 3. n = e / 2 4. use b and n in a nested-if to determine the shape based on Table 2.

Note that Step 1 determines the (simplified) number of valence electrons v for the central atom A. Step 2 subtracts the number of bonding domains (b) from v to determine the number of nonbonding electrons (e). Then, by dividing e by 2, Step 3 determines the number of bonding domains (n). We assume that only single bonds are present. Also, Table 1 shows the element name only for your convenience; it is not required in the C++ program.

Each line in the input file, called molecules.txt and given on UR Courses, represents the information for one molecule and contains 3 pieces of data in the following format: A B b where A and B are the chemical symbols for two elements (use type string), and b is the number of B atoms (use type int).

In the output file, called geometricalshapes.txt, print the determined shape in this format: The geometrical shape of one A atom surrounded by b B atoms is s., where s is the determined shape from Table 2. Indicate s as unknown when the values of b and n do not match any case in Table 2.

For example, if the first four input lines from molecules.txt are

O F 2 S F 4 Be F 3 C P 1

then the first four output lines in geometricalshapes.txt would be

The geometrical shape of one O atom surrounded by 2 F atoms is bent. The geometrical shape of one S atom surrounded by 4 F atoms is seesaw. The geometrical shape of one Be atom surrounded by 3 F atoms is trigonal planar. The geometrical shape of one C atom surrounded by 1 P atoms is unknown.

Table 1 Element Symbol v Beryllium Be 3 Carbon C 4 Silicon Si 4 Nitrogen N 5 Phosphorus P 5 Arsenic As 5 Oxygen O 6 Sulfur S 6 Selenium Se 6 Flourine F 7 Chlorine Cl 7 Bromine Br 7 Iodine I 7 Xenon Xe 8

Table 2 b n s (Molecular Geometry) 2 0 linear 2 1 bent 2 2 bent 2 3 linear 3 0 trigonal planar 3 1 trigonal pyramidal 3 2 T-shaped 4 0 tetrahedral 4 1 seesaw 4 2 square planar 5 0 trigonal bipyramidal 5 1 square pyramidal 6 0 octahedral

Use meaningful variable names, proper indentation, and appropriate comments.