回文链表问题

Posted 2022-02-08 Alice_yufeng

/**
 * Definition for singly-linked list.
 * public class ListNode 
 *     int val;
 *     ListNode next;
 *     ListNode() 
 *     ListNode(int val)  this.val = val; 
 *     ListNode(int val, ListNode next)  this.val = val; this.next = next; 
 * 
 */
class Solution 
    public boolean isPalindrome(ListNode head) 
        List<Integer> vals = new ArrayList<Integer>();

        // 将链表的值复制到数组中
        ListNode currentNode = head;
        while (currentNode != null) 
            vals.add(currentNode.val);
            currentNode = currentNode.next;
        

        // 使用双指针判断是否回文
        int front = 0;
        int back = vals.size() - 1;
        while (front < back) 
            if (!vals.get(front).equals(vals.get(back))) 
                return false;
            
            front++;
            back--;
        
        return true;