Day 9.0

day_09.rb

@@ -0,0 +1,38 @@
+require "letters"
+distances = Hash.new {|h,k| h[k] = {} }
+DATA.read.scan(/^(.*) to (.*) = (.*)$/).each do |from, to, distance|
+  distance = distance.to_i
+  distances[to][from] = distance
+  distances[from][to] = distance
+end
+locations = distances.keys
+puts locations.permutation.map {|p| p.each_cons(2).map {|a,b| distances[a][b] }.inject(&:+) }.min
+__END__
+Faerun to Tristram = 65
+Faerun to Tambi = 129
+Faerun to Norrath = 144
+Faerun to Snowdin = 71
+Faerun to Straylight = 137
+Faerun to AlphaCentauri = 3
+Faerun to Arbre = 149
+Tristram to Tambi = 63
+Tristram to Norrath = 4
+Tristram to Snowdin = 105
+Tristram to Straylight = 125
+Tristram to AlphaCentauri = 55
+Tristram to Arbre = 14
+Tambi to Norrath = 68
+Tambi to Snowdin = 52
+Tambi to Straylight = 65
+Tambi to AlphaCentauri = 22
+Tambi to Arbre = 143
+Norrath to Snowdin = 8
+Norrath to Straylight = 23
+Norrath to AlphaCentauri = 136
+Norrath to Arbre = 115
+Snowdin to Straylight = 101
+Snowdin to AlphaCentauri = 84
+Snowdin to Arbre = 96
+Straylight to AlphaCentauri = 107
+Straylight to Arbre = 14
+AlphaCentauri to Arbre = 46