Airbnb - File System

https://github.com/allaboutjst/airbnb/blob/master/README.md

Write a file system class, which has two functions: create, and get

• create("/a",1)
• get("/a") //get 1
• create("/a/b",2)
• get("/a/b") //get 2
• create("/c/d",1) //Error, because "/c" is not existed
• get("/c") //Error, because "/c" is not existed

https://github.com/allaboutjst/airbnb/blob/master/src/main/java/file_system/FileSystem.java

        Map<String, Integer> pathMap;
        Map<String, Runnable> callbackMap;

        public Solution() {
            this.pathMap = new HashMap<>();
            this.callbackMap = new HashMap<>();
            this.pathMap.put("", 0);
        }

        public boolean create(String path, int value) {
            if (pathMap.containsKey(path)) {
                return false;
            }

            int lastSlashIndex = path.lastIndexOf("/");
            if (!pathMap.containsKey(path.substring(0, lastSlashIndex))) {
                return false;
            }

            pathMap.put(path, value);
            return true;
        }

        public boolean set(String path, int value) {
            if (!pathMap.containsKey(path)) {
                return false;
            }

            pathMap.put(path, value);

            // Trigger callbacks
            String curPath = path;
//            while (curPath.length() > 0) {
//                if (callbackMap.containsKey(curPath)) {
//                    callbackMap.get(curPath).run();
//                }
//                int lastSlashIndex = path.lastIndexOf("/");
//                curPath = curPath.substring(0, lastSlashIndex);
//            }

            return true;
        }

        public Integer get(String path) {
            return pathMap.get(path);
        }

        public boolean watch(String path, Runnable callback) {
            if (!pathMap.containsKey(path)) {
                return false;
            }

            callbackMap.put(path, callback);
            return true;
        }