[LeetCode] 71. Simplify Path Java

题目：

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

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

题意及分析：给出一个unix的绝对路径，简化路径，.表示当前目录，../表示上级目录。使用一个Stack保存目录即可，遇到“”、“.”跳过；遇到“..”，若stack不为空弹出栈顶元素；遇到其他字符串直接入栈。

代码：

class Solution {
    public String simplifyPath(String path) {
        if(path.equals("/"))
            return path;
        String[] strings = path.split("/");
        Stack<String > stack  = new Stack<>();
        for(int i=0;i<strings.length;i++){
            if(strings[i].equals("") || strings[i].equals("."))
                continue;
            else if(strings[i].equals("..")){
                if(stack.size()>0)
                    stack.pop();
            }else
                stack.push(strings[i]);
        }
        if(stack.isEmpty())
            return "/";
        String res = "";
        while(!stack.isEmpty()){
            res = "/" + stack.pop() + res;
        }
        return res;
    }
}