input2.txt

It can be useful for a writer to make sure they are using variety of
sentence lengths, or to ensure none of their sentences are too long.
Let's build a tool that evaluates a text file for sentence length.

Choosing the appropriate container key when using the STL. If you need
something ordered, it's often best to use an associative container, such
as map or multimap. In this case, however, since we need a descending
sort, it's easier to sort a vector. 

The vector is generally the most flexible of the STL containers.
Whenever another container type seems appropriate, but is missing one
important capability, the vector is often an effective solution. In this
case, where we need our output sorted in descending order, the vector
works great.

This recipe uses a vector of vectors. The inner vector stores the words
of a sentence, and the outer vector stores the inner vectors. As you'll
see, this affords a lot of flexibility while retaining all the relevant
data.