examples/rosettacode/first_letter_last_letter.nit

   1 #!/usr/bin/env nit
   2 #
   3 # This file is part of NIT ( http://www.nitlanguage.org ).
   4 # This program is public domain
   5
   6 # Task: Last letter-first letter
   7 # SEE: <http://rosettacode.org/wiki/Last letter-first letter>
   8 module first_letter_last_letter
   9
  10 fun search(words: String): Array[String]
  11 do
  12         var list = words.split("[ \n]".to_re)
  13         var res = search_2(new Array[String], list)
  14         return res
  15 end
  16
  17 fun search_2(state, remain: Array[String]): Array[String]
  18 do
  19         if remain.is_empty then return state
  20         var last
  21         var res = state
  22         if state.is_empty then last = null else last = state.last.chars.last
  23         for word in remain do
  24                 if last != null and word.chars.first != last then continue
  25                 var new_state = state + [word]
  26                 var new_remain = remain.clone
  27                 new_remain.remove(word)
  28                 var sub_res = search_2(new_state, new_remain)
  29                 if sub_res.length > res.length then
  30                         res = sub_res
  31                 end
  32         end
  33         return res
  34 end
  35
  36 var words = """audino bagon baltoy banette bidoof braviary
  37 bronzor carracosta charmeleon cresselia croagunk darmanitan deino
  38 emboar emolga exeggcute gabite girafarig gulpin haxorus heatmor
  39 heatran ivysaur jellicent jumpluff kangaskhan kricketune landorus
  40 ledyba loudred lumineon lunatone machamp magnezone mamoswine nosepass
  41 petilil pidgeotto pikachu pinsir poliwrath poochyena porygon2
  42 porygonz registeel relicanth remoraid rufflet sableye scolipede
  43 scrafty seaking sealeo silcoon simisear snivy snorlax spoink starly
  44 tirtouga trapinch treecko tyrogue vigoroth vulpix wailord wartortle
  45 whismur wingull yamask"""
  46 print search(words).join("\n")