Most common substring of length X

Question

I have a string s and I want to search for the substring of length X that occurs most often in s. Overlapping substrings are allowed.

For example, if s=\"aoaoa\" and X=3

Answer 1

It should be O(n*m) where m is the average length of a string in the list. For very small values of m then the algorithm will approach O(n)

• Build a hashtable of counts for each string length
• Iterate over your collection of strings, updating the hashtable accordingly, storing the current most prevelant number as an integer variable separate from the hashtable
• done.