Essential things to remember from today's class (class 4, 30th August)

How to use strtod and strtol, or stod and stoi.
   With stod and stoi you should almost always make use of the optional
   second parameter.

Be aware of the useful string methods.
   No need to memorise the details of all of them, but you really must
   be familiar with what exists.

What "graph" means in computing.

How to make a recursive exploration of a graph work,
   although not necessarily very efficiently.