6、JAVA實現單鏈表的逆序

方法1

public class Node {int data;Node next = null;public Node(int data){this.data = data;}public static Node reverseSingleLink(Node head){Node front = null;Node succ = null;Node p = head.next;//不知道是不是如果不帶頭結點，就是p = head了？還是搞不清楚頭結點這個東西。while(p != null){succ = p.next;p.next = front;front = p;p = succ;}return front;}public static void main(String[] args){Node head = new Node(0);Node tail = head; for(int i = 1 ; i < 4; ++i){          Node p = new Node(i);          tail.next = p;          tail = p;                     }                    head = reverseSingleLink(head);             while(head!= null){                         System.out.println(head.data);                head = head.next;            }}}

方法3、我還沒有看懂。遞迴方法。

public class List {        Node head;      Node tail;   public void reverse0(List list) {          Node last = reverse(list.head);          list.tail = last;          list.tail.next = null;      }            public Node reverse(Node hd) {                if (hd == null) {              return null;          } else if (hd.next == null) {              head = hd;  // the last one becomes the head          } else {              Node node = reverse(hd.next);              node.next = hd;          }          return hd;      } }     class Node {      int data;      Node next;            public Node(int i) {          data = i;      } }