feat: add ts solution to lcci problem: No.02.06

No.02.06.Palindrome Linked List

Author: YangFong

lcci/02.06.Palindrome Linked List/README.md

@@ -249,6 +249,35 @@ function isPalindrome(head: ListNode | null): boolean {
 }
 ```
 
+```ts
+/**
+ * Definition for singly-linked list.
+ * class ListNode {
+ *     val: number
+ *     next: ListNode | null
+ *     constructor(val?: number, next?: ListNode | null) {
+ *         this.val = (val===undefined ? 0 : val)
+ *         this.next = (next===undefined ? null : next)
+ *     }
+ * }
+ */
+
+function isPalindrome(head: ListNode | null): boolean {
+    let root = head;
+    const dfs = (node: ListNode | null): boolean => {
+        if (node == null) {
+            return true;
+        }
+        if (dfs(node.next) && node.val === root.val) {
+            root = root.next;
+            return true;
+        }
+        return false;
+    };
+    return dfs(head);
+}
+```
+
 ### **Go**
 
 ```go

lcci/02.06.Palindrome Linked List/README_EN.md

@@ -249,6 +249,35 @@ function isPalindrome(head: ListNode | null): boolean {
 }
 ```
 
+```ts
+/**
+ * Definition for singly-linked list.
+ * class ListNode {
+ *     val: number
+ *     next: ListNode | null
+ *     constructor(val?: number, next?: ListNode | null) {
+ *         this.val = (val===undefined ? 0 : val)
+ *         this.next = (next===undefined ? null : next)
+ *     }
+ * }
+ */
+
+function isPalindrome(head: ListNode | null): boolean {
+    let root = head;
+    const dfs = (node: ListNode | null): boolean => {
+        if (node == null) {
+            return true;
+        }
+        if (dfs(node.next) && node.val === root.val) {
+            root = root.next;
+            return true;
+        }
+        return false;
+    };
+    return dfs(head);
+}
+```
+
 ### **Go**
 
 ```go