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| class Solution {
ListNode root = null;
public ListNode swapPairs(ListNode head) {
if(head == null){
return head;
}
return dfs(head);
}
public ListNode dfs(ListNode root){
if(root == null){
return root;
}
ListNode node1 = new ListNode(root.val);
if(root.next == null){
return node1;
}
ListNode node2 = new ListNode(root.next.val);
node2.next = node1;
node1.next = dfs(root.next.next);
return node2;
}
}
|
