fixup ruby code

1 files changed, 27 insertions, 9 deletions

diff --git a/assignments/2/README.md b/assignments/2/README.md
index a15d33f..36b810f 100644
--- a/assignments/2/README.md
+++ b/assignments/2/README.md
@@ -335,21 +335,39 @@ d. 192.53.56.7 -> no /23 match -> forward using Default -> Router 3.
 ```ruby
 require 'ipaddr'
 
-routes = [
-  IPAddr.new('135.46.56.0/22'),
-  IPAddr.new('135.46.60.0/22'),
-  IPAddr.new('192.53.40.0/23'),
-]
+class RoutingTable
+  def initialize(default, routes)
+    @default = default
+    @routes = routes
+  end
+
+  def route_to(ip)
+    @routes.fetch(@routes.keys.find { |route| route.include?(ip) }, @default)
+  end
+end
+
+table = RoutingTable.new("Router 3", {
+  IPAddr.new('135.46.56.0/22') => "Interface 0",
+  IPAddr.new('135.46.60.0/22') => "Interface 1",
+  IPAddr.new('192.53.40.0/23') => "Router 2",
+})
 
 a = IPAddr.new("135.46.61.10")
 b = IPAddr.new("135.46.53.16")
 c = IPAddr.new("192.53.40.6")
 d = IPAddr.new("192.53.56.7")
 
-puts routes.find { |route| route.include?(a) } || "Default"
-puts routes.find { |route| route.include?(b) } || "Default"
-puts routes.find { |route| route.include?(c) } || "Default"
-puts routes.find { |route| route.include?(d) } || "Default"
+puts table.route_to(a)
+puts table.route_to(b)
+puts table.route_to(c)
+puts table.route_to(d)
+```
+
+```bash
+Interface 1
+Router 3
+Router 2
+Router 3
 ```
 
 ## 2.4 TCP Congestion Control (20%)