AtCoder ABC #057 [Ruby]

abc057-a.rb

# A. Remaining Time
a, b = gets.chomp.split(" ").map(&:to_i)
if (a + b) >= 24 then
  puts (a + b) - 24
else
  puts (a + b)
end

abc057-b.rb

# B. Checkpoints
n, m = gets.chomp.split(" ").map(&:to_i)
ab = []
n.times do
  ab << gets.chomp.split(" ").map(&:to_i)
end

cd = []
m.times do
  cd << gets.chomp.split(" ").map(&:to_i)
end

ab.each do |a, b|
  cp = cd.map{|c, d| (a - c).abs + (b - d).abs}
  puts cp.index(cp.min) + 1
end

abc057-c.rb

# C. Digits in Multiplication
n = gets.chomp.to_i
upper = Math.sqrt(n).to_i
ret = n.to_s.length
(1..upper).each do |i|
  if n % i == 0 then
    curr = ([i, n / i].max).to_s.length
    ret = [ret, curr].min
  end
end
puts ret

abc057-d.rb

# D. Maximum Average Sets
n, a, b = gets.chomp.split(" ").map(&:to_i)
v = gets.chomp.split(" ").map(&:to_i).sort.reverse

def comb_table(n)
  ct = Array.new(51){Array.new(51, 0)}
  (0..n).each do |i|
    (0..i).each do |j|
      if j == 0 || j == i then
        ct[i][j] = 1
      else
        ct[i][j] = ct[i-1][j-1] + ct[i-1][j]
      end
    end
  end
  return ct
end
ct = comb_table(n)

ave = v[0..(a-1)].inject(:+) / a.to_f
puts sprintf("%f", ave)

a_th_val_num = 0
a_th_val_pos = 0

n.times do |i|
  if v[i] == v[a-1] then
    a_th_val_num += 1
    if i < a then
      a_th_val_pos += 1
    end
  end
end

cnt = 0
if v[0] == v[a-1] then
  (a..b).each do |i|
    cnt += ct[a_th_val_num][i]
  end
else
  cnt += ct[a_th_val_num][a_th_val_pos]
end

puts cnt