https://leetcode.com/problems/design-add-and-search-words-data-structure/description/

trie.rb

class TrieNode
  attr_accessor :childrens, :leaf
  def initialize
    self.childrens = {}
    self.leaf = false
  end
end

class WordDictionary

  def initialize
    @root = TrieNode.new
  end

  def add_word(word)
    return if word.length < 0 || word.length > 25

    temp = @root
    word.each_char do |c|
      temp.childrens[c] ||= TrieNode.new
      temp = temp.childrens[c]
    end
    temp.leaf = true if temp.childrens.empty?
  end

  def search(word)
    temp = @root
    puts dfs(temp, word, 0)
    dfs(temp, word, 0)
  end

  def dfs(node, word, index)
    if word[index] == "."
      node.childrens.each do |k, child|
        return true if child.leaf && index == word.length - 1

        return dfs(child, word, index + 1)
      end
    elsif node.childrens.key?(word[index])
      child = node.childrens[word[index]]
      return true if child.leaf && index == word.length - 1

      return dfs(child, word, index + 1)
    end

    false
  end
end


wordDictionary = WordDictionary.new
["WordDictionary","addWord","addWord","addWord","addWord","search","search","addWord","search","search","search","search","search","searc"].each do |word|
  wordDictionary.add_word(word)
end
wordDictionary.search("pad")
wordDictionary.search("bad")
wordDictionary.search("s..rch")
wordDictionary.search("search")
wordDictionary.search(".ad")
wordDictionary.search("b..")
wordDictionary.search("c..")