Two-Hundred-Fourteen Commit: Add Design Add and Search Words Data Structure problem to Trie Section

Author: AAdewunmi

src/Trie/Problem_3_Design_Add_And_Search_Words_Data_Structure.java

@@ -0,0 +1,52 @@
+package Trie;
+
+// Problem Statement: Design Add and Search Words Data Structure (medium)
+// LeetCode Question: 211. Design Add and Search Words Data Structure
+
+public class Problem_3_Design_Add_And_Search_Words_Data_Structure {
+
+    class TrieNode {
+    TrieNode[] children = new TrieNode[26];
+    boolean isEnd = false;
+    }
+
+    private TrieNode root;
+
+    public Problem_3_Design_Add_And_Search_Words_Data_Structure() {
+        root = new TrieNode();
+    }
+
+    public void addWord(String word) {
+        TrieNode node = root;
+        for (char c : word.toCharArray()) {
+            if (node.children[c - 'a'] == null) {
+                node.children[c - 'a'] = new TrieNode();
+            }
+            node = node.children[c - 'a'];
+        }
+        node.isEnd = true;
+    }
+
+    public boolean search(String word) {
+        return searchInNode(word, root);
+    }
+
+    private boolean searchInNode(String word, TrieNode node) {
+        for (int i = 0; i < word.length(); i++) {
+            char ch = word.charAt(i);
+            if (ch == '.') {
+                for (TrieNode child : node.children) {
+                    if (child != null && searchInNode(word.substring(i + 1), child)) {
+                        return true;
+                    }
+                }
+                return false;
+            } else {
+                if (node.children[ch - 'a'] == null) return false;
+                node = node.children[ch - 'a'];
+            }
+        }
+        return node.isEnd;
+    }
+
+}