单链表的逆置

单链表的逆置。例如：输入字符串abcd，输出字符串dcba

class Lnode{
  char data;
  Lnode next;
}

public class Main {	
  //返回带头结点的单链表L的逆转链表
  public static Lnode Reverse( Lnode L ) {
      Lnode Old_head, New_head, Temp;
      New_head = null;
      Old_head = L.next;
      while ( Old_head != null )  {
          Temp = Old_head.next;
         Old_head.next= New_head;
         New_head = Old_head;  
         Old_head = Temp; 
      }
     L.next= New_head;
     return L
  }

public static void main(String[] args) {
    String str = null;
    Lnode La = new Lnode();
    La.next = null;
    Lnode r = La;  //尾指针
    Lnode Lb = new Lnode();
   Scanner scanner = new Scanner(System.in);
   str = scanner.next();
    //尾插法
    for(int i=0; i