Added implementTrie solution

Author: nhistory

implement-trie-prefix-tree/nhistory.js

@@ -0,0 +1,51 @@
+var Trie = function () {
+  this.root = {};
+};
+
+/**
+ * @param {string} word
+ * @return {void}
+ */
+Trie.prototype.insert = function (word) {
+  let node = this.root;
+  for (let char of word) {
+    if (!node[char]) {
+      node[char] = {};
+    }
+    node = node[char];
+  }
+  node.isEndOfWord = true;
+};
+
+/**
+ * @param {string} word
+ * @return {boolean}
+ */
+Trie.prototype.search = function (word) {
+  let node = this.root;
+  for (let char of word) {
+    if (!node[char]) {
+      return false;
+    }
+    node = node[char];
+  }
+  return node.isEndOfWord === true;
+};
+
+/**
+ * @param {string} prefix
+ * @return {boolean}
+ */
+Trie.prototype.startsWith = function (prefix) {
+  let node = this.root;
+  for (let char of prefix) {
+    if (!node[char]) {
+      return false;
+    }
+    node = node[char];
+  }
+  return true;
+};
+
+// TC: O(n)
+// SC: O(n)