Today I am trying to create suffix arrays using scala. I was able to do it with massive lines of code but then I heard that it can be created by using only few lines by using zipping and sorting.
The problem I have at the moment is with the beginning. I tried using binary search and zipWithIndex to create the following "tree" but so far I haven't been able to create anything. I don't even know if it is possible by only using a line but I bet it is lol.
What I want to do is to get from a word "cheesecake" is a Seq:
Seq((cheesecake, 0),
(heesecake, 1),
(eesecake, 2),
(esecake, 3),
(secake, 4),
(ecake, 5),
(cake, 6),
(ake, 7),
(ke, 8),
(e, 9))
Could someone nudge me to the correct path ?
To generate all the possible postfixes of a String (or any other scala.collection.TraversableLike) you can simply use the tails method:
scala> "cheesecake".tails.toList
res25: List[String] = List(cheesecake, heesecake, eesecake, esecake, secake, ecake, cake, ake, ke, e, "")
If you need the indexes, then you can use GenIterable.zipWithIndex:
scala> "cheesecake".tails.toList.zipWithIndex
res0: List[(String, Int)] = List((cheesecake,0), (heesecake,1), (eesecake,2), (esecake,3), (secake,4), (ecake,5), (cake,6), (ake,7), (ke,8), (e,9), ("",10))