Given an absolute path for a file (Unix-style), simplify it.

For example,

path = "/home/", => "/home"

path = "/a/./b/../../c/", => "/c"

Corner Cases:

 

• Did you consider the case where path = "/../"?
  In this case, you should return "/".
• Another corner case is the path might contain multiple slashes '/' together, such as "/home//foo/".
  In this case, you should ignore redundant slashes and return "/home/foo".

 

ref:http://fisherlei.blogspot.com/2013/01/leetcode-simplify-path.html

[解题思路]

利用栈的特性，如果sub string element

1. 等于“/”，跳过，直接开始寻找下一个element

2. 等于“.”，什么都不需要干，直接开始寻找下一个element

3. 等于“..”，弹出栈顶元素，寻找下一个element

4. 等于其他，插入当前elemnt为新的栈顶，寻找下一个element

最后，再根据栈的内容，重新拼path。这样可以避免处理连续多个“/”的问题。

public class Solution {    public String simplifyPath(String path) {        ArrayList
      
        sta=new ArrayList
       
        ();        String[] paths=path.split("/");        for(int i=0;i