Japt: Count overlapping substrings

16th February 2021

Finding the number of overlapping needles in a haystack in Japt is slightly verbose, clocking in at 12 bytes, but still a fun fiddling exercise for a change.

ðV      // Get all indices of needle in the input.
äÏ-X<Vl
ä       // For every consecutive pair of indices
 Ï-X    // check whether their distance
    <Vl // is smaller than the needle length, e.g. whether they overlap.
è       // Return the number of items that were true.