Best shuffle: Difference between revisions

== {{header|Crystal}} ==

{{trans|ruby}}

<lang ruby>def best_shuffle(s)

# Fill _pos_ with positions in the order

# that we want to fill them.

pos = [] of Int32

# g["a"] = [2, 4] implies that s[2] == s[4] == "a"

g = s.size.times.group_by { |i| s[i] }

# k sorts letters from low to high count

# k = g.sort_by { |k, v| v.length }.map { |k, v| k } # in Ruby

k = g.to_a.sort_by { |e| e[1].size }.map { |e| e[0] }

until g.empty?

k.each do |letter|

g.has_key?(letter) || next # g[letter] || next

pos << g[letter].pop

g[letter].empty? && g.delete letter

end

end

# Now fill in _new_ with _letters_ according to each position

# in _pos_, but skip ahead in _letters_ if we can avoid

# matching characters that way.

letters = s.dup

new = "?" * s.size

until letters.empty?

i, p = 0, pos.pop

while letters[i] == s[p] && i < (letters.size - 1); i += 1 end

# new[p] = letters.slice! i # in Ruby

new = new.sub(p, letters[i]); letters = letters.sub(i, "")

end

score = new.chars.zip(s.chars).count { |c, d| c == d }

{new, score}

end

%w(abracadabra seesaw elk grrrrrr up a).each do |word|

# puts "%s, %s, (%d)" % [word, *best_shuffle(word)] # in Ruby

new, score = best_shuffle(word)

puts "%s, %s, (%d)" % [word, new, score]

end</lang>

{{out}}

<pre>

abracadabra, baarrcadaab, (0)

seesaw, essewa, (0)

elk, lke, (0)

grrrrrr, rgrrrrr, (5)

up, pu, (0)

a, a, (1)

</pre>