Swap Nodes in Pairs

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) {
 *         val = x;
 *         next = null;
 *     }
 * }
 */
public class Solution {
    public ListNode swapPairs(ListNode head) {
        // Note: The Solution object is instantiated only once and is reused by each test case.
        if(head == null || head.next == null) return head;
        ListNode temp = head;
        ListNode current = head;
        ListNode result = head.next;
        while(current != null && current.next != null)
        {
            temp = current.next.next;
            current.next.next = current;
            if(temp != null && temp.next != null){  
                current.next = temp.next;
            }
            else{   //odd elements
                current.next = temp;
            }
            current = temp; //next pair of nodes
        }
        return result;
    }
}