Create: 0211-design-add-and-search-words-data-structure.scala

Author: ChrisKheng

scala/0211-design-add-and-search-words-data-structure.scala

@@ -0,0 +1,70 @@
+import scala.collection.mutable.HashMap
+
+class WordDictionary() {
+    val trie = new Trie()
+
+    def addWord(word: String) {
+        trie.insert(word) 
+    }
+
+    def search(word: String): Boolean = {
+        trie.search(word)
+    }
+
+}
+
+class Trie() {
+    class TrieNode {
+        val children: HashMap[Char, TrieNode] = HashMap()
+        var isEndOfWord = false
+    }
+
+    private var root: TrieNode = new TrieNode()
+
+    def insert(word: String): Unit = {
+        var curr = root
+        word.foreach(c => {
+            if (!curr.children.contains(c)) {
+                curr.children(c) = new TrieNode()                
+            }
+
+            curr = curr.children(c)
+        })
+
+        curr.isEndOfWord = true
+    }
+
+    def search(word: String): Boolean = {
+        def helper(currNode: TrieNode, currCharIndex: Int): Boolean = {
+            if (currCharIndex == word.length) {
+                return currNode.isEndOfWord
+            }
+
+            val currChar = word(currCharIndex)
+            if (currChar == '.') {
+                var isFound = false 
+
+                for ((_, childNode) <- currNode.children if !isFound) {
+                    isFound = helper(childNode, currCharIndex + 1)
+                }
+
+                return isFound 
+            } else {
+                if (currNode.children.contains(currChar)) {
+                    return helper(currNode.children(currChar), currCharIndex + 1) 
+                } else {
+                    return false 
+                }
+            }
+        } 
+
+        helper(root, 0)
+    }
+}
+
+/**
+ * Your WordDictionary object will be instantiated and called as such:
+ * var obj = new WordDictionary()
+ * obj.addWord(word)
+ * var param_2 = obj.search(word)
+ */