Codeforces #328 Div2

cf328_div2_a_PawnChess.rb

# [Problem - 592A - Codeforces](http://codeforces.com/problemset/problem/592/A)
field = []
while line = gets
  field << line.chomp.split("")
end
field = field.transpose
stepA = []
stepB = []
field.each do |r|
  a = r.rindex("W")
  b = r.rindex("B")
  unless b.nil? then
    if a.nil? or (a < b) then
      stepB << 7 - b
    end
  end
  a = r.index("W")
  b = r.index("B")
  unless a.nil? then
    if b.nil? or (a < b) then
      stepA << a
    end
  end
end
if stepB.empty? or (stepA.min <= stepB.min) then
  puts "A"
elsif stepA.empty? or (stepA.min > stepB.min) then
  puts "B"
end

cf328_div2_b_TheMonsterandtheSquirrel

# [Problem - 592B - Codeforces](http://codeforces.com/problemset/problem/592/B)
n = gets.chomp.to_i
if n == 3 then
  puts 1
else
  a1 = 1
  4.upto(n).each do |a|
    a1 += 3 + 2*(a-4)
  end
  puts a1
end

cf328_div2_c_TheBigRace.rb

# [Problem - 592C - Codeforces](http://codeforces.com/problemset/problem/592/C)
t, w, b = gets.chomp.split(" ").map(&:to_i)
res = 0
(1..t).each do |i|
  ww = i / w
  www = w * ww
  bb = i / b
  bbb = b * bb
  if www ==bbb then
    res += 1
  end
end
puts Rational(res, t)

• A
• B
• C
• D
• E