class Solution {
public ListNode swapPairs(ListNode head) {
ListNode dummy = new ListNode(0);//定義啞結點
dummy.next = head;//連線啞結點與頭結點
ListNode current = dummy;//current負責具體操作
while(current.next != null && current.next.next != null){
ListNode node1 = current.next;
ListNode node2 = current.next.next;
current.next = node2;
node1.next = node2.next;
node2.next = node1;
current = node1;
}
return dummy.next;
}
}
交換中
交換後