Java代码 两种方法反转单链表 _表 两种方法反转单链表 _表_02

  1. /**
  2. * @author luochengcheng
  3. * 定义一个单链表
  4. */
  5. class Node {
  6. //变量
  7. private int record;
  8. //指向下一个对象
  9. private Node nextNode;
  10.  
  11. public Node(int record) {
  12. super();
  13. this.record = record;
  14. }
  15. public int getRecord() {
  16. return record;
  17. }
  18. public void setRecord(int record) {
  19. this.record = record;
  20. }
  21. public Node getNextNode() {
  22. return nextNode;
  23. }
  24. public void setNextNode(Node nextNode) {
  25. this.nextNode = nextNode;
  26. }
  27. }
  28.  
  29. /**
  30. * @author luochengcheng
  31. * 两种方式实现单链表的反转(递归、普通)
  32. * 新手强烈建议旁边拿着纸和笔跟着代码画图(便于理解)
  33. */
  34. public class ReverseSingleList {
  35. /**
  36. * 递归，在反转当前节点之前先反转后续节点
  37. */
  38. public static Node reverse(Node head) {
  39. if (null == head || null == head.getNextNode()) {
  40. return head;
  41. }
  42. Node reversedHead = reverse(head.getNextNode());
  43. head.getNextNode().setNextNode(head);
  44. head.setNextNode(null);
  45. return reversedHead;
  46. }
  47.  
  48. /**
  49. * 遍历，将当前节点的下一个节点缓存后更改当前节点指针
  50. *
  51. */
  52. public static Node reverse2(Node head) {
  53. if (null == head) {
  54. return head;
  55. }
  56. Node pre = head;
  57. Node cur = head.getNextNode();
  58. Node next;
  59. while (null != cur) {
  60. next = cur.getNextNode();
  61. cur.setNextNode(pre);
  62. pre = cur;
  63. cur = next;
  64. }
  65. //将原链表的头节点的下一个节点置为null，再将反转后的头节点赋给head
  66. head.setNextNode(null);
  67. head = pre;
  68.  
  69. return head;
  70. }
  71.  
  72. public static void main(String[] args) {
  73. Node head = new Node(0);
  74. Node tmp = null;
  75. Node cur = null;
  76. // 构造一个长度为10的链表，保存头节点对象head
  77. for (int i = 1; i < 10; i++) {
  78. tmp = new Node(i);
  79. if (1 == i) {
  80. head.setNextNode(tmp);
  81. } else {
  82. cur.setNextNode(tmp);
  83. }
  84. cur = tmp;
  85. }
  86. //打印反转前的链表
  87. Node h = head;
  88. while (null != h) {
  89. System.out.print(h.getRecord() + " ");
  90. h = h.getNextNode();
  91. }
  92. //调用反转方法
  93. head = reverse2(head);
  94. System.out.println("\n**************************");
  95. //打印反转后的结果
  96. while (null != head) {
  97. System.out.print(head.getRecord() + " ");
  98. head = head.getNextNode();
  99. }
  100. }
  101. }