CSAcademy Round #50

csa050-a.rb

# Travel Distance
x = 0
y = 0
gets.chomp.split("").each do |d|
  if d == "N"
    y += 1
  elsif d == "E"
    x += 1
  elsif d == "S"
    y -= 1
  else
    x -= 1
  end
end
puts x.abs + y.abs

csa050-b.rb

# Friday 13
d = [31,28,31,30,31,30,31,31,30,31,30,31]
a = ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"]
jan1 = a.index(gets.chomp)

doy = 0
ans = 0
d.each do |dom|
  (1..dom).each do |i|
    doy += 1
    if (doy + jan1) % 7 == 5 && i == 13 then
      ans += 1
    end
  end
end

puts ans

csa050-c.rb

# Check Square
def dot(a, b, c)
  v1 = [b[0] - a[0], b[1] - a[1]]
  v2 = [c[0] - b[0], c[1] - b[1]]
  return v1[0] * v2[0] + v1[1] * v2[1]
end

def dist(a, b)
  return (b[0] - a[0])**2 + (b[1] - a[1])**2
end

def square?(perm)
  a1 = dot(perm[0], perm[1], perm[2]) == 0
  a2 = dot(perm[1], perm[2], perm[3]) == 0
  a3 = dot(perm[2], perm[3], perm[0]) == 0
  a4 = dot(perm[3], perm[0], perm[1]) == 0
  return a1 && a2 && a3 && a4 && dist(perm[0], perm[1]) && dist(perm[1], perm[2]) && dist(perm[2], perm[3]) && dist(perm[3], perm[0])
end

gets.chomp.to_i.times do
  done = false
  ps = []
  ls = []
  4.times do
    x, y = gets.chomp.split(" ").map(&:to_i)
    ps << [x, y]
  end
  ps.permutation do |perm|
    if square?(perm)
      puts 1
      done = true
      break
    end
  end
  puts 0 if !done
end