DDPC 2016 予選

ddpc2016qual-a.rb

s = "DiscoPresentsDiscoveryChannelProgrammingContest2016"
w = gets.chomp.to_i
n = s.length
a = n / w
b = n % w
 
i = 0
a.times do
  puts s[i...(i + w)]
  i += w
end
if b > 0 then
  puts s[(n - b)...n]
end

ddpc2016qual-b.rb

n = gets.chomp.to_i
a = gets.chomp.split(" ").map(&:to_i)

h = Hash.new{|h,k| h[k] = []}
n.times do |i|
  h[a[i]] << i
end
pos = 0
res = 1
h.keys.sort.each do |k|
  v = h[k]
  if v.first < pos && v.last > pos then
    res += 1
    pos = (v.select{|x| x < pos}).last
  elsif v.last < pos then
    res += 1
    pos = v.last
  else
    pos = v.last
  end
end
res -= 1 if pos == 0
puts res

# ref: Submission #624244

ddpc2016qual-c.rb

s = gets.chomp
k = gets.chomp.to_i

def f(s, k)
  if k <= 0 then
    return [s]
  end
  res = []
  (0...(s.length)).each do |i|
    res << s[0...i] + s[(i+1)..-1]
    res << s[0...i] + "a" + s[(i + 1)..-1]
  end
  res << s[0...-1]
  res << "a" + s
  rr = []
  res.each do |r|
    rr += f(r, k-1)
  end
  return rr
end

if s.length > 10 then
  puts -1
  exit
end
ans = f(s, k).min
if ans == "" then
  ans = "a"
end
puts ans

# ref: Submission #625127