feat: add javascript solution to lcci problem: No.02.01.Remove Duplicate Node (doocs#366)

Author: zhaocchen

lcci/02.01.Remove Duplicate Node/README.md

@@ -102,6 +102,38 @@ class Solution {
 }
 ```
 
+### **JavaScript**
+
+```javascript
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val) {
+ *     this.val = val;
+ *     this.next = null;
+ * }
+ */
+/**
+ * @param {ListNode} head
+ * @return {ListNode}
+ */
+ var removeDuplicateNodes = function(head) {
+    if (head == null || head.next == null) return head;
+    const cache = new Set([]);
+    cache.add(head.val);
+    let cur = head, fast = head.next;
+    while (fast !== null) {
+        if (!cache.has(fast.val)) {
+            cur.next = fast;
+            cur = cur.next;
+            cache.add(fast.val);
+        }
+        fast = fast.next;
+    }
+    cur.next = null;
+    return head;
+};
+```
+
 ### **...**
 
 ```

lcci/02.01.Remove Duplicate Node/README_EN.md

@@ -103,6 +103,38 @@ class Solution {
 }
 ```
 
+### **JavaScript**
+
+```javascript
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val) {
+ *     this.val = val;
+ *     this.next = null;
+ * }
+ */
+/**
+ * @param {ListNode} head
+ * @return {ListNode}
+ */
+ var removeDuplicateNodes = function(head) {
+    if (head == null || head.next == null) return head;
+    const cache = new Set([]);
+    cache.add(head.val);
+    let cur = head, fast = head.next;
+    while (fast !== null) {
+        if (!cache.has(fast.val)) {
+            cur.next = fast;
+            cur = cur.next;
+            cache.add(fast.val);
+        }
+        fast = fast.next;
+    }
+    cur.next = null;
+    return head;
+};
+```
+
 ### **...**
 
 ```

lcci/02.01.Remove Duplicate Node/Solution.js

@@ -0,0 +1,27 @@
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val) {
+ *     this.val = val;
+ *     this.next = null;
+ * }
+ */
+/**
+ * @param {ListNode} head
+ * @return {ListNode}
+ */
+ var removeDuplicateNodes = function(head) {
+    if (head == null || head.next == null) return head;
+    const cache = new Set([]);
+    cache.add(head.val);
+    let cur = head, fast = head.next;
+    while (fast !== null) {
+        if (!cache.has(fast.val)) {
+            cur.next = fast;
+            cur = cur.next;
+            cache.add(fast.val);
+        }
+        fast = fast.next;
+    }
+    cur.next = null;
+    return head;
+};