Add design-add-and-search-words-data-structure solution in TypeScript

Author: Jeehay28

design-add-and-search-words-data-structure/Jeehay28.ts

@@ -0,0 +1,73 @@
+class WordDictionary {
+  root: {
+    [key: string]: any;
+  };
+
+  constructor() {
+    this.root = { $: true }; // ending
+  }
+
+  // {
+  //   "$": true,
+  //   "b": {
+  //     "$": false,
+  //     "a": {
+  //       "$": false,
+  //       "d": {
+  //         "$": true
+  //       }
+  //     }
+  //   }
+  // }
+
+  // TC: O(w)
+  // SC: O(w)
+  addWord(word: string): void {
+    let node = this.root;
+
+    for (const ch of word) {
+      if (!node[ch]) {
+        node[ch] = { $: false };
+      }
+      node = node[ch];
+    }
+
+    node["$"] = true;
+  }
+
+  // TC: O(26^w)
+  // SC: O(w)
+  search(word: string): boolean {
+    const dfs = (node, idx: number) => {
+      if (idx === word.length) {
+        return node["$"];
+      }
+
+      const ch = word[idx];
+
+      if (node[ch]) {
+        return dfs(node[ch], idx + 1);
+      }
+
+      if (ch === ".") {
+        for (const key of Object.keys(node)) {
+          if (key !== "$" && dfs(node[key], idx + 1)) {
+            return true;
+          }
+        }
+      }
+
+      return false;
+    };
+
+    return dfs(this.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)
+ */
+