Constructor for a Bigram struct.

Get the bigram frequencies as a sorted array.

Max to report.

Max to store.

A struct to hold an instance of a Bigram Since they could be either simplified or traditional, index by the headwordids.

Single record of the frequency of occurence of a bigram.

Sorted into descending order with most frequent bigram first.

Map of the frequency of occurence of a bigram in a collection of texts.

The key is the headword id, each entry is a bigram frequency map.