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  1. f = -> n {
  2.   pn = -> n {n.to_s.reverse.to_i == n ? [n] : []}
  3.   aux = -> m, a, b {0 < m.size ? m : aux.(pn.(a) + pn.(b), a - 1, a + 1)}
  4.   aux.(pn.(n), n - 1, n + 1)
  5. }
  6. p [0, 17, 100].map {|n| [n, f.(n)]}
Success #stdin #stdout 0.01s 8112KB
comments (?)
stdin 
Standard input is empty
stdout 
[[0, [0]], [17, [11]], [100, [99, 101]]]
https://ideone.com/0pvK4o
language:
Ruby (ruby 2.5.5)
created:
93 days ago
visibility:
secret

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