August 23, 2024
P10 - Run-length encoding of a list.
Use the result of problem P09 to implement the so-called run-length encoding data compression method. Consecutive duplicates of elements are encoded as tuples (N, E) where N is the number of duplicates of the element E.
Example:
> p10:encode(['a', 'a', 'a', 'a', 'b', 'c', 'c', 'a', 'a', 'd', 'e', 'e', 'e', 'e']).
[{4,a},{1,b},{2,c},{2,a},{1,d},{4,e}]erlang
%Run-length encoding of a list.
-module(p10).
-export([encode/1]).
encode(Ls) ->
A = p09:pack(Ls),
lists:map(fun([Head | Tail]) -> {length(Tail) + 1, Head} end , A).
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