LeetCode 71 Simplify Path

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"

.

思路：简单题，Unix文件的根目录为"/"，"."表示当前目录，".."表示上级目录

public class Solution {
    public String simplifyPath(String path) {
    	String []strs=path.split("/");
    	StringBuilder sb=new StringBuilder("");
    	LinkedList<String> ll=new LinkedList<String>();
    	for(String str:strs){
    		if(str.equals(".")) continue;
    		else if(str.equals("..")&&!ll.isEmpty()) {
    				ll.pollLast();
    		}else if(str.length()>0&&!str.equals("..")){
    			ll.add(str);
    		}
    	}
    	if(ll.isEmpty())return "/";
    	for(String str:ll){
    		sb.append("/");
    		sb.append(str);
    	}
    	return sb.toString();
    }
}