1. ArrayList 和 LinkedList 的区别

http://pengcqu.iteye.com/blog/502676

 

 

2. How to reverse LinkedList

http://www.java2blog.com/2014/07/how-to-reverse-linked-list-in-java.html

 

/**
 * Definition for ListNode.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 * 
 *     ListNode(int val) {
 *         this.val = val;
 *         this.next = null;
 *     }
 * }
 */ 
public class Solution {
    /**
     * @param head: The head of linked list.
     * @return: The new head of reversed linked list.
     */
    public ListNode reverse(ListNode head) {
        ListNode preNode = null;
        ListNode nextNode;
        ListNode curNode = head;
        while(curNode != null){
            nextNode = curNode.next;
            curNode.next = preNode;
            preNode = curNode;
            curNode = nextNode;
        }
        return preNode;// write your code here
    }
}