Commit 68a2dcc

@@ -0,0 +1,39 @@
+#!/usr/bin/env ruby
+
+=begin
+Given a string, find the length of the longest substring without repeating characters.
+
+class Solution:
+  def lengthOfLongestSubstring(self, s):
+    # Fill this in.
+
+print Solution().lengthOfLongestSubstring('abrkaabcdefghijjxxx')
+# 10
+
+Can you find a solution in linear time?
+=end
+
+def assert_equal(x, y)
+  raise [x, y].inspect unless x == y
+end
+
+class Solution
+  def self.length_of_longest_substring(value)
+    last = nil
+    count = 0
+    max = 0
+    value.chars.each_with_index do |char, i|
+      if char == last
+        count = 1
+      else
+        count += 1
+      end
+      max = count if count > max
+      last = char
+    end
+    max
+  end
+end
+
+assert_equal 10, Solution.length_of_longest_substring('abrkaabcdefghijjxxx')
+puts "Yay!"