update the solutions(remove redundant)

Author: realdennis

src/trie/implement-trie-prefix-tree.ts

@@ -1,6 +1,5 @@
 class Trie {
     private map: Map<string, Trie> = new Map();
-    constructor() {}
     insert(word: string): void {
         if (word === "") {
             this.map.set("#", new Trie());

src/trie/longest-common-prefix.ts

@@ -0,0 +1,39 @@
+export default {};
+
+function longestCommonPrefix(strs: string[]): string {
+    class TrieNode {
+        isEnd = false;
+        mem: Map<string, TrieNode> = new Map();
+    }
+
+    class Trie {
+        root: TrieNode = new TrieNode();
+        insert = (str: string): void => {
+            let ptr = this.root;
+            for (const ch of str) {
+                if (!ptr.mem.has(ch)) ptr.mem.set(ch, new TrieNode());
+                ptr = ptr.mem.get(ch)!;
+            }
+            ptr.isEnd = true;
+        };
+        searchPrefix = (): string => {
+            let ptr = this.root;
+            let ret = "";
+            while (
+                ptr &&
+                ptr.mem.size === 1 /* multiple childs */ &&
+                ptr.isEnd === false /* end condition*/
+            ) {
+                const key = ptr.mem.keys().next().value;
+                ret += key;
+                ptr = ptr.mem.get(key)!;
+            }
+            return ret;
+        };
+    }
+    const trie = new Trie();
+
+    for (const str of strs) trie.insert(str);
+
+    return trie.searchPrefix();
+}