Submission #3285131

---

Source Code Expand

n = gets.to_i
a = n.times.map{gets.to_i}.sort
b = n.times.map{gets.to_i}.sort

$mod = 10**9+7
$fact = Array.new(100010,1)

for i in 2..100000
  $fact[i] = $fact[i-1]*i%$mod
end

def clac(a,b,n)
  ret = 1
  l = r = 0
  while r < n
    if a[r] < b[l]
      r += 1
    else
      ret *= $fact[r-l]
      ret %= $mod
      r += 1 if l == r
      l = r
    end
  end
  return (ret*$fact[n-l])%$mod
end

puts (clac(a,b,n)*clac(b,a,n))%$mod

Submission Info

Judge Result