Example 1:
Input: ["FileSystem","ls","mkdir","addContentToFile","ls","readContentFromFile"]
[[],["/"],["/a/b/c"],["/a/b/c/d","hello"],["/"],["/a/b/c/d"]]
Output: [null, [], null, null, ["a"], "hello"]
Explanation:
Example 2:
Input: ["FileSystem","mkdir","addContentToFile","addContentToFile","readContentFromFile","ls"]
[[],["/x/y"],["/x/y/file","abc"],["/x/y/file","def"],["/x/y/file"],["/x/y/file"]]
Output: [null, null, null, null, "abcdef", ["file"]]
Design a data structure that simulates an in-memory file system.
Implement the FileSystem class:
FileSystem() Initializes the object.List<String> ls(String path) If path is a file path, returns a list that only contains this file's name. If path is a directory path, returns the list of file and directory names in this directory.void mkdir(String path) Makes a new directory according to the given path. The given directory path does not exist. If the middle directories in the path do not exist, create them as well.void addContentToFile(String filePath, String content) If filePath does not exist, creates that file containing content. If filePath already exists, appends content to the original content.String readContentFromFile(String filePath) Returns the content in the file at filePath.FileSystem fs = new FileSystem(); fs.ls("/"); // [] fs.mkdir("/a/b/c"); fs.addContentToFile("/a/b/c/d", "hello"); fs.ls("/"); // ["a"] fs.readContentFromFile("/a/b/c/d"); // "hello"
1 <= path.length, filePath.length <= 100path and filePath are absolute paths that begin with / and do not end with / except for the root path /.1 <= content.length <= 50ls, mkdir, addContentToFile, and readContentFromFile will be called at most 300 times in total.