Exact string matching

How do I write a code, that finds repeated words from an input file and prints those with its position, i.e. (where it was found)

[Jan]

Please post, what you have done already and ask for a specific question. This forum is not a programming robot and we will not solve your homework.

[Gurusaran]

Dear Simon,

I have scripted the above mentioned problem in perl and I am just curious and a bit sure that it can can also be done in matlab(I am new to matlab). More over, mine is just a naive algorithm. My aim is to implement efficient string algorithms like Suffix array or Suffix tree. All I wanted to know is, Is it feasible to implement such complicated algorithm in matlab or is there any better way doing this in matlab.

[Gurusaran]

And brother, this is not my homework nor you have to do it for me, I'm just curious and need a kick start.

[Jan]

Ok, no homework. Even if you are new at Matlab, I assume you can implement the reading of a text file by your own. Then it would be useful if you implement as much as you can and ask a specific question. For such general questions there is a discrepancy between the effort needed to create a meaningful answer, and the effort shown by the author.

Answer 1

[Walter Roberson]

Read the file in to a string, newlines and all. Use regex() to extract the "words" and corresponding locations (for whatever you define a "word" to be.) Use the three-output form of unique() to get the unique words and the corresponding indices into the original list of words. Index the location list by that index list to get the word positions.

Biggest trick: you will need to set two optional modes for regex, as shown here