solve: implement trie prefix tree

Author: JustHm

implement-trie-prefix-tree/JustHm.swift

@@ -0,0 +1,35 @@
+
+class Trie {
+    var children: [Character: Trie] = [:]
+    var isEndOfWord = false
+
+    func insert(_ word: String) {
+        guard !word.isEmpty else { return }
+        var node = self
+        for char in word {
+            if node.children[char] == nil {
+                node.children[char] = Trie()
+            }
+            node = node.children[char]!
+        }
+        node.isEndOfWord = true
+    }
+
+    func search(_ word: String) -> Bool {
+        guard let node = findNode(word) else { return false }
+        return node.isEndOfWord
+    }
+
+    func startsWith(_ prefix: String) -> Bool {
+        return findNode(prefix) != nil
+    }
+
+    private func findNode(_ word: String) -> Trie? {
+        var node = self
+        for char in word {
+            guard let next = node.children[char] else { return nil }
+            node = next
+        }
+        return node
+    }
+}