LeetCode-simplify-path

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

For example,
path ="/home/", =>"/home"
path ="/a/./b/../../c/", =>"/c"

click to show corner cases.

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".

import java.util.*;
public class Solution {
    public String simplifyPath(String path) {
        String[] dirs = path.split("/");
        ArrayList<String> dirList = new ArrayList<>();
        for(int i=0;i<dirs.length;i++){
            if(dirs[i].equals(".") || dirs[i].equals("")){
                continue;
            }else if(dirs[i].equals("..")){
                if(dirList.size()>0)
                    dirList.remove(dirList.size()-1);
            }else{
                dirList.add(dirs[i]);
            }
        }
        StringBuilder res = new StringBuilder();
        for(String dir:dirList){
            res.append("/").append(dir);
        }
        if(res.length()==0){
            res.append("/");
        }
        return res.toString();
    }
}