Created 208-Implement-Trie

typescript/208-Implement-Trie.ts

@@ -0,0 +1,61 @@
+class TrieNode {
+ children: {};
+ endOfWord: boolean;
+ constructor() {
+ this.children = {};
+ this.endOfWord = false;
+ }
+}
+
+class Trie {
+ root: TrieNode;
+ constructor() {
+ this.root = new TrieNode();
+ }
+
+ insert(word: string): void {
+ let cur = this.root;
+
+ for (const c of word) {
+ if (!(c in cur.children)) {
+ cur.children[c] = new TrieNode();
+ }
+ cur = cur.children[c];
+ }
+ cur.endOfWord = true;
+ }
+
+ search(word: string): boolean {
+ let cur = this.root;
+
+ for (const c of word) {
+ if (!(c in cur.children)) {
+ return false;
+ }
+ cur = cur.children[c];
+ }
+
+ return cur.endOfWord;
+ }
+
+ startsWith(prefix: string): boolean {
+ let cur = this.root;
+
+ for (const c of prefix) {
+ if (!(c in cur.children)) {
+ return false;
+ }
+ cur = cur.children[c];
+ }
+
+ return true;
+ }
+}
+
+const trie = new Trie();
+trie.insert("apple");
+trie.search("apple"); // return True
+trie.search("app"); // return False
+trie.startsWith("app"); // return True
+trie.insert("app");
+trie.search("app"); // return True