Ruby solution for week 103, part 2

2 files changed, 68 insertions, 0 deletions

diff --git a/challenge-103/abigail/README.md b/challenge-103/abigail/README.md
index bbf2a50037..d35895761f 100644
--- a/challenge-103/abigail/README.md
+++ b/challenge-103/abigail/README.md
@@ -126,5 +126,6 @@ Output:
 * [Lua](lua/ch-2.lua)
 * [Perl](perl/ch-2.pl)
 * [Python](python/ch-2.py)
+* [Ruby](ruby/ch-2.rb)
 
 ### Blog
diff --git a/challenge-103/abigail/ruby/ch-2.rb b/challenge-103/abigail/ruby/ch-2.rb
new file mode 100644
index 0000000000..f4695983a4
--- /dev/null
+++ b/challenge-103/abigail/ruby/ch-2.rb
@@ -0,0 +1,67 @@
+#!/usr/bin/ruby
+
+#
+# See ../README.md
+#
+ 
+#
+# Run as: ruby ch-2.rb < input-file
+#
+
+#
+# We're reading a start time, the current time, and a file name
+# from STDIN, separated by white space. The file contains the
+# tracks played.
+#
+
+ARGF . each_line do |_|
+    start_time, end_time, file_name = _ . split
+
+    #
+    # Ruby automatically creates big integers if necessary.
+    #
+    time_diff = (end_time . to_i - start_time . to_i) * 1000
+
+    tracks = []
+    total_time = 0
+    File . open (file_name) do |f|
+        f . each_line do |track|
+            run_time, title = track . split ',', 2
+            run_time = run_time . to_i
+            total_time += run_time
+            tracks . push [run_time, title]
+        end
+    end
+
+    #
+    # We're not interested in playing full loops.
+    #
+    time_diff %= total_time
+
+    #
+    # Find the current track playing. If $time_diff is less than the
+    # play time of the track, this is the track currently playing. If
+    # so, print the track name (with quotes, as given in the example --
+    # although they don't belong there, as they're from the CSV encoding;
+    # for that reason, we won't deescape anything else either). Otherwise
+    # (track length is shorter than $time_diff), we subtrack the length
+    # of the track from $time_diff, and continue checking the next track.
+    #
+    tracks . each do |track|
+        if time_diff - track [0] < 0
+            time_diff =  (time_diff / 1000)       . to_i
+            hours     =  (time_diff / 3600)       . to_i
+            minutes   = ((time_diff % 3600) / 60) . to_i
+            seconds   =   time_diff         % 60
+            puts (track [1])
+            if hours > 0
+                puts "%02d:%02d:%02d" % [hours, minutes, seconds]
+            else
+                puts      "%02d:%02d" % [       minutes, seconds]
+            end
+            break
+        else
+            time_diff -= track [0]
+        end
+    end
+end