aparler/RosettaCodeData
1
0
Fork 0
Code Issues 12 Pull requests 3 Projects Releases Packages Wiki Activity Actions

2016 Update

Browse source
This commit is contained in:
Tina Müller 2016-12-05 22:15:40 +01:00
parent 948b86eafa
commit dcf5d15da3
7965 changed files with 139854 additions and 31002 deletions
Download patch file Download diff file Expand all files Collapse all files

14
Task/Longest-common-subsequence/Elixir/longest-common-subsequence-1.elixir Normal file
View file

@ -0,0 +1,14 @@
defmodule LCS do
def lcs(a, b) do
lcs(to_charlist(a), to_charlist(b), []) |> to_string
end
defp lcs([h|at], [h|bt], res), do: lcs(at, bt, [h|res])
defp lcs([_|at]=a, [_|bt]=b, res) do
Enum.max_by([lcs(a, bt, res), lcs(at, b, res)], &length/1)
end
defp lcs(_, _, res), do: res |> Enum.reverse
end
IO.puts LCS.lcs("thisisatest", "testing123testing")
IO.puts LCS.lcs('1234','1224533324')

28
Task/Longest-common-subsequence/Elixir/longest-common-subsequence.elixir → Task/Longest-common-subsequence/Elixir/longest-common-subsequence-2.elixir
View file

@ -1,36 +1,34 @@
defmodule LCS do
def lcs_length(s,t) do
{l,_c} = lcs_length(s,t,Map.new)
l
end
def lcs_length(s,t), do: lcs_length(s,t,Map.new) |> elem(0)
defp lcs_length([],t,cache), do: {0,Dict.put(cache,{[],t},0)}
defp lcs_length(s,[],cache), do: {0,Dict.put(cache,{s,[]},0)}
defp lcs_length([],t,cache), do: {0,Map.put(cache,{[],t},0)}
defp lcs_length(s,[],cache), do: {0,Map.put(cache,{s,[]},0)}
defp lcs_length([h|st]=s,[h|tt]=t,cache) do
{l,c} = lcs_length(st,tt,cache)
{l+1,Dict.put(c,{s,t},l+1)}
{l+1,Map.put(c,{s,t},l+1)}
end
defp lcs_length([_sh|st]=s,[_th|tt]=t,cache) do
if Dict.has_key?(cache,{s,t}) do
{Dict.get(cache,{s,t}),cache}
if Map.has_key?(cache,{s,t}) do
{Map.get(cache,{s,t}),cache}
else
{l1,c1} = lcs_length(s,tt,cache)
{l2,c2} = lcs_length(st,t,c1)
l = Enum.max([l1,l2])
{l,Dict.put(c2,{s,t},l)}
l = max(l1,l2)
{l,Map.put(c2,{s,t},l)}
end
end
def lcs(s,t) do
{s,t} = {to_charlist(s),to_charlist(t)}
{_,c} = lcs_length(s,t,Map.new)
lcs(s,t,c,[])
lcs(s,t,c,[]) |> to_string
end
defp lcs([],_,_,acc), do: Enum.reverse(acc)
defp lcs(_,[],_,acc), do: Enum.reverse(acc)
defp lcs([h|st],[h|tt],cache,acc), do: lcs(st,tt,cache,[h|acc])
defp lcs([_sh|st]=s,[_th|tt]=t,cache,acc) do
if Dict.get(cache,{s,tt}) > Dict.get(cache,{st,t}) do
if Map.get(cache,{s,tt}) > Map.get(cache,{st,t}) do
lcs(s,tt,cache,acc)
else
lcs(st,t,cache,acc)
@ -38,5 +36,5 @@ defmodule LCS do
end
end
IO.puts LCS.lcs('thisisatest','testing123testing')
IO.puts LCS.lcs('1234','1224533324')
IO.puts LCS.lcs("thisisatest","testing123testing")
IO.puts LCS.lcs("1234","1224533324")