71. Simplify Path

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

For example,

path = "/home/", => "/home"

path = "/a/./b/../../c/", => "/c"

三刷简化了一下代码 使用jdk1.8新特性 switch支持String

    public String simplifyPath(String path) {
        Stack<String> stack = new Stack<>();
        for (String s : path.split("/")) {
            switch (s) {
                case "" :
                case ".":
                    break;
                case "..":
                    if (!stack.isEmpty()) stack.pop();
                    break;
                default:
                    stack.push("/"+s);
                    break;
            }
        }
        return stack.isEmpty() ? "/" : String.join("", stack);
    }

需要注意的是 

stack extends vector

vector extends abstractlist 

所以stack也是iterable的 可以直接用在string.join中