208

ruby/208-Implement-Trie.rb

@@ -0,0 +1,38 @@
+class Trie
+ END_OF_WORD = 'END'
+
+ def initialize
+ @root = {}
+ end
+
+ def insert(word)
+ curr = @root
+ last_idx = word.length - 1
+ word.each_char.with_index do |char, idx|
+ curr[char] ||= {}
+ curr = curr[char]
+ curr[END_OF_WORD] = true if last_idx == idx
+ end
+ nil
+ end
+
+ def search(word)
+ curr = @root
+ word.each_char do |char|
+ return false unless curr[char]
+
+ curr = curr[char]
+ end
+ !!curr[END_OF_WORD]
+ end
+
+ def starts_with(prefix)
+ curr = @root
+ prefix.each_char do |char|
+ return false unless curr[char]
+
+ curr = curr[char]
+ end
+ true
+ end
+end