This is a small programming problem to test your technical ability and coding style.
Write a simple script to generate a set of n-grams from a string of text. N-grams are a contiguous sequence of n words from a string of text, and have many applications from full-text search indexes to machine learning.
You'll generate a set of every permutation of contiguous n-grams from a string of text, from 1-gram to n-grams where n is the number of words in the string