Add solution #234

Author: JoshCrozier

README.md

@@ -37,6 +37,7 @@
 217|[Contains Duplicate](./0217-contains-duplicate.js)|Easy|
 219|[Contains Duplicate II](./0219-contains-duplicate-ii.js)|Easy|
 226|[Invert Binary Tree](./0226-invert-binary-tree.js)|Easy|
+234|[Palindrome Linked List](./0234-palindrome-linked-list.js)|Easy|
 263|[Ugly Number](./0263-ugly-number.js)|Easy|
 264|[Ugly Number II](./0264-ugly-number-ii.js)|Medium|
 268|[Missing Number](./0268-missing-number.js)|Easy|

solutions/0234-palindrome-linked-list.js

@@ -0,0 +1,30 @@
+/**
+ * 234. Palindrome Linked List
+ * https://leetcode.com/problems/palindrome-linked-list/
+ * Difficulty: Easy
+ *
+ * Given the `head` of a singly linked list, return `true` if it is a palindrome.
+ */
+
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val, next) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.next = (next===undefined ? null : next)
+ * }
+ */
+/**
+ * @param {ListNode} head
+ * @return {boolean}
+ */
+var isPalindrome = function(head) {
+  let a = '', b = '';
+
+  while (head) {
+    a = a + head.val;
+    b = head.val + b;
+    head = head.next;
+  }
+
+  return a === b;
+};