[算法学习]求链表的中间结点

参考代码如下

[code]static class ListNode
{
    int val;
    ListNode next;

    public ListNode(int val)
    {
        this.val = val;
    }

    public ListNode(int val, ListNode next)
    {
        this.val = val;
        this.next = next;
    }

    @Override
    public String toString()
    {
        return "ListNode [val=" + val + "]";
    }
}

/**
 * 返回中间节点
 * @param head
 * @return
 */
public static ListNode[] getCenterNode(ListNode head)
{
    ListNode[] results = { null, null };
    if (head == null)
    {
        return results;
    }
    ListNode left = head;
    ListNode right = head.next;
    // 如果只有一个节点
    if (right == null)
    {
        results[0] = left;
        return results;
    }
    // 如果不止有一个节点
    while (right.next != null)
    {
        left = left.next;
        right = right.next;
        right = right.next;
        if (right == null)
        {
            results[0] = left;
            return results;
        }
    }
    results[0] = left;
    results[1] = left.next;
    return results;
}