Reversing a Linked List

[pleasanton]

方法很多，请贴一个你认为最好的方法

[pleasanton]

谁能看懂下面的CODE？晕哪

public class MyLinkedList {
	Node first, last = null;

	class Node {
		public int data;
		public Node next;
	}
		
	void addNode(int data) {
		Node myNode = new Node();
		myNode.data = data;
		myNode.next =null;

		if (first == null)
			first = myNode;
		if (last != null)
			last.next = myNode;
		last = myNode;
	}
	
	public void reverse() {
		
		if (null == first)
			return;
			
		Node p = null;
		Node c = first;
		Node n = c.next;
		
		c.next = p;
		while (n != null) {
			p = c; c = n; n = n.next; c.next = p;
		}
	
		Node t = first;
		first = last;
		last = t;
	}  
	
	void print() {
		for (Node myNode = first; myNode != null ; myNode = myNode.next ) 
			System.out.print(myNode.data +",");
		
	}

	//---------------------main()--------------------------
	public static void main(String[] args) {
		MyLinkedList myLinkedList = new MyLinkedList();

		myLinkedList.addNode(1);
		myLinkedList.addNode(2);
		myLinkedList.addNode(3);
		myLinkedList.addNode(4);
		myLinkedList.addNode(5);
		 	 
		myLinkedList.print();		
		
		myLinkedList.reverse();
		System.out.println();
		myLinkedList.print();		
	}
}

[尘缘udbwcso]

引用 8 楼 u011405885 的回复:

谁能看懂下面的CODE？晕哪

public class MyLinkedList {
	Node first, last = null;

	class Node {
		public int data;
		public Node next;
	}
		
	void addNode(int data) {
		Node myNode = new Node();
		myNode.data = data;
		myNode.next =null;

		if (first == null)
			first = myNode;
		if (last != null)
			last.next = myNode;
		last = myNode;
	}
	
	public void reverse() {
		
		if (null == first)
			return;
			
		Node p = null;
		Node c = first;
		Node n = c.next;
		
		c.next = p;
		while (n != null) {
			p = c; c = n; n = n.next; c.next = p;
		}
	
		Node t = first;
		first = last;
		last = t;
	}  
	
	void print() {
		for (Node myNode = first; myNode != null ; myNode = myNode.next ) 
			System.out.print(myNode.data +",");
		
	}

	//---------------------main()--------------------------
	public static void main(String[] args) {
		MyLinkedList myLinkedList = new MyLinkedList();

		myLinkedList.addNode(1);
		myLinkedList.addNode(2);
		myLinkedList.addNode(3);
		myLinkedList.addNode(4);
		myLinkedList.addNode(5);
		 	 
		myLinkedList.print();		
		
		myLinkedList.reverse();
		System.out.println();
		myLinkedList.print();		
	}
}

以前学C语言的时候写的和这个相似 java有已经实现了的，直接用就好了 如果是想了解链表看一下数据结构

[尘缘udbwcso]

int len = link.size(); while(len > 0){ link.poolLast(link.offerFirst()); --len; }

[pleasanton]

引用 9 楼 udbwcso 的回复:

以前学C语言的时候写的和这个相似 java有已经实现了的，直接用就好了 如果是想了解链表看一下数据结构

改成这样，我就懂了

	Node previous = null;
		Node current = first;
		Node next = current.nextNode;
		
		current.nextNode = null; 
		while (next != null) {
			previous = current; 
			current = next; 
			next = next.nextNode; 
			current.nextNode = previous;
		
		}
	
		Node tep = first;
		first = last;
		last = tep;

[pleasanton]

link.offerFirst() 有问题？

[pleasanton]

ll.offerFirst(ll.pollLast());?

[尘缘udbwcso]

随手写的，没有编译没有运行过，只是个思路而已 要是不知道那个方法是干啥的可以看一下api

[huntor]

Collections public static void reverse(List<?> list)

[pleasanton]

引用 4 楼 udbwcso 的回复:

随手写的，没有编译没有运行过，只是个思路而已 要是不知道那个方法是干啥的可以看一下api

多谢。我下面这个参考了你的思路，但有点笨

	public LinkedList reverse(LinkedList ll){
		LinkedList llResault = new LinkedList();
		int len = ll.size();
		while (len > 0) {
			llResault.add(ll.pollLast());
			--len;
		}
		return llResault;
		
	}

[pleasanton]

引用 5 楼 huntor 的回复:

Collections public static void reverse(List<?> list)

没看懂？ 大师能帮我改一下上面的CODE吗？ 我不太会用<?>