Leetcode71简化路径

代码：

class Solution {
    public String simplifyPath(String path) {
        String[] names = path.split("/");
        Deque stack = new ArrayDeque();
        for(String name: names){
            if(name.equals("..")){
                if(!stack.isEmpty()){
                    stack.pollLast();
                }
            }else if(name.length()>0&&!".".equals(name)){
                stack.offerLast(name);
            }
        }
        StringBuffer ans = new StringBuffer();
        if(stack.isEmpty()){
            ans.append('/');
        }else{
            while(!stack.isEmpty()){
                ans.append('/');
                ans.append(stack.pollFirst());
            }
        }
        return ans.toString();
    }
}

stack的一些用法