feat(soobing): implement-trie-prefix-tree

Author: soobing

implement-trie-prefix-tree/soobing.ts

@@ -0,0 +1,46 @@
+class TrieNode {
+  children: Map<string, TrieNode>;
+  isEnd: boolean;
+
+  constructor() {
+    this.children = new Map();
+    this.isEnd = false;
+  }
+}
+
+class Trie {
+  root: TrieNode;
+
+  constructor() {
+    this.root = new TrieNode();
+  }
+
+  insert(word: string): void {
+    let node = this.root;
+    for (const char of word) {
+      if (!node.children.has(char)) {
+        node.children.set(char, new TrieNode());
+      }
+      node = node.children.get(char)!;
+    }
+    node.isEnd = true;
+  }
+
+  search(word: string): boolean {
+    const node = this._findNode(word);
+    return node !== null && node.isEnd;
+  }
+
+  startsWith(prefix: string): boolean {
+    return this._findNode(prefix) !== null;
+  }
+
+  private _findNode(word: string): TrieNode | null {
+    let node = this.root;
+    for (const char of word) {
+      if (!node.children.has(char)) return null;
+      node = node.children.get(char)!;
+    }
+    return node;
+  }
+}