SwapTwoNodesInLinkedList.java

/**                                                                                 
  ,dW"Yvd `7MMpMMMb.pMMMb.  M"""MMV     ,p6"bo   ,pW"Wq.`7MMpMMMb.pMMMb.      ,6"Yb.`7MM  `7MM  
 ,W'   MM   MM    MM    MM  '  AMV     6M'  OO  6W'   `Wb MM    MM    MM     8)   MM  MM    MM  
 8M    MM   MM    MM    MM    AMV      8M       8M     M8 MM    MM    MM      ,pm9MM  MM    MM  
 YA.   MM   MM    MM    MM   AMV  , ,, YM.    , YA.   ,A9 MM    MM    MM  ,, 8M   MM  MM    MM  
  `MbmdMM .JMML  JMML  JMML.AMMmmmM db  YMbmd'   `Ybmd9'.JMML  JMML  JMML.db `Moo9^Yo.`Mbod"YML.
       MM                                                                                       
     .JMML.                                                                                     
       
 * This code snippet is copyright at qmz.com.au
 * - qmz.com.au is a top-ranking IT consulting firm that specialised in
 * - Mobile Development, Web Development, Machine Learning, and Cloud Computing.
 * - We provide individual and company training for professional development.
 * - Find out more information in our official site：
 * - https://qmz.com.au                                                                   
 */

// Given a linked list and two values v1 and v2. Swap the two nodes in the linked list with values v1 and v2. It's guaranteed there is no duplicate values in the linked list. If v1 or v2 does not exist in the given linked list, do nothing.

// Example
// Example 1:

// Input: 1->2->3->4->null, v1 = 2, v2 = 4
// Output: 1->4->3->2->null
// Example 2:

// Input: 1->null, v1 = 2, v2 = 1
// Output: 1->null
// Notice
// You should swap the two nodes with values v1 and v2. Do not directly swap the values of the two nodes.


/**
 * Definition for ListNode
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) {
 *         val = x;
 *         next = null;
 *     }
 * }
 */

public class Solution {
  /**
   * @param head: a ListNode
   * @param v1: An integer
   * @param v2: An integer
   * @return: a new head of singly-linked list
   */
  public ListNode swapNodes(ListNode head, int v1, int v2) {
      // write your code here
  }
}