A text analyser

The problem

Build a tool that reads a text file and reports its word count, its most common words and its longest lines.

Requirements

• Reads any text file named by the user, and reports a missing file clearly
• Counts lines, words and characters
• Ignores case and punctuation when counting words
• Lists the ten most common words, with ties in alphabetical order
• Uses standard algorithms and containers rather than hand-written sorting
• Prints the results in aligned columns

Technologies

• C++
• File streams
• map and vector
• Standard algorithms
• iomanip

Step by step

1. Read the file line by line with getline, and count the lines and characters.
2. Write a function that cleans a word by lower-casing it and removing punctuation.
3. Split each line with a string stream, and count the words in a map.
4. Copy the map into a vector of pairs.
5. Sort the vector with a compare function, by count and then by word.
6. Print the top ten with setw.
7. Test with an empty file and with a file that does not exist.

Expected result

A useful tool that summarises any text file, built almost entirely from the standard library.

How it is evaluated

• The counts are correct for an empty file
• Words differing only in case count as one
• Ties are ordered correctly
• The output lines up

Ways to improve it

• Accept several files at once
• Exclude common words such as the and and
• Show a text histogram of word lengths