public ListNodes Method(ListNodes head)
{
//处理特殊情况
if (head == null || head.next == null)
{
return(head);
}
ListNodes pre = head.next;
//first,second为当前要交换的节点，last为上一次交换后末尾的节点
ListNodes first, second, last = null;
first = head;
second = first.next;
while (first != null && first.next != null)
{
if (second != null)
{
//交换前后节点
first.next = second.next;
second.next = first;
//将当前末尾的节点指向刚交换的节点，并重设last
if (last != null)
{
last.next = second;
}
last = first;
}
//将指针指向下一对要交换的节点
first = first.next;
if (first != null)
{
second = first.next;
}
}
return(pre);
}
public ListNodes(int val = 0, ListNodes next = null)
{
this.val = val;
this.next = next;
}
