菜鸟急求一道JAVA题,高手们花几分钟提点一下小弟吧.不胜感激
模版是这样的
package Chap05.linkList;
// linkList.java
// demonstrates linked list
// to run this program: C> java LinkListApp
////////////////////////////////////////////////////////////////
class Link
{
public int iData; // data item
public double dData; // data item
public Link next; // next link in list
// -------------------------
public Link(int id, double dd) // constructor
{
iData = id; // initialize data
dData = dd; // ( 'next ' is automatically
} // set to null)
// -------------------------
public void displayLink() // display ourself
{
System.out.print( "{ " + iData + ", " + dData + "} ");
}
} // end class Link
////////////////////////////////////////////////////////////////
class LinkList
{
private Link first; // ref to first link on list
// -------------------------
public LinkList() // constructor
{
first = null; // no links on list yet
}
// -------------------------
public boolean isEmpty() // true if list is empty
{
return (first==null);
}
// -------------------------
// insert at start of list
public void insertFirst(int id, double dd)
{ // make new link
Link newLink = new Link(id, dd);
newLink.next = first; // newLink --> old first
first = newLink; // first --> newLink
}
// -------------------------
public Link deleteFirst() // delete first item
{ // (assumes list not empty)
Link temp = first; // save reference to link
first = first.next; // delete it: first--> old next
return temp; // return deleted link
}
// -------------------------
public void displayList()
{
System.out.print( "List (first--> last): ");
Link current = first; // start at beginning of list
while(current != null) // until end of list,
{
current.displayLink(); // print data
current = current.next; // move to next link
}
System.out.println( " ");
}
// -------------------------
} // end class LinkList
////////////////////////////////////////////////////////////////
public class linkListApp
{
public static void main(String[] args)
{
LinkList theList = new LinkList(); // make new list
theList.insertFirst(22, 2.99); // insert four items
theList.insertFirst(44, 4.99);
theList.insertFirst(77, 7.99);
theList.insertFirst(66, 6.99);
theList.insertFirst(88, 8.99);
theList.insertFirst(99, 9.99);
theList.displayList(); // display list
while( !theList.isEmpty() ) // until it 's empty,
{
Link aLink = theList.deleteFirst(); // delete link
System.out.print( "Deleted "); // display it
aLink.displayLink();
System.out.println( " ");
}
theList.displayList(); // display list
} // end main()
} // end class LinkListApp
////////////////////////////////////////////////////////////////
现在有2个要求.
1 对于一个单向链表，写一个方法
int getLast(int n), 这个方法返回链表倒数第n个节点(就是要键盘输入一个数.然后就返回倒数第N个节点)
2 写一个方法
void reverse(), 将这个链表反向(递归?一头雾水啊.高人拉小弟一把吧)
[解决办法]
这个是改进版，代码更简洁，效率更高！！！
//这是个公共函数，也就是你需要的接口
public void reverse() {
Link temp = first;
reverselink(temp).next = null;
}
//这是个私有函数，为上面的公共函数服务
private Link reverselink(Link l) {
if(l.next==null){
first = l;
return l;
}
reverselink(l.next).next = l;
return l;
}
