Design a Basic File System
Solve a medium-level problem for developing basic file system operations using tries.
Problem statement
Design a file system that allows you to create new text files and add content to them.
The paths in this file system are a set of strings concatenated by slashes ("/").
For example, “home” and “/home/ben” are valid paths, while an empty string and “/” are not.
Currently, this file system supports the following operations.
createFile: This allows the users to create a file and add data to it. The function should take in the file path and the content as input, create a new file at the given path, and add text content to it. It should return false if the path file already exists or its parent path doesn’t exist.
getFileData: This allows the users to fetch the data stored in a file. It returns the data stored in the file if the file exists and returns -1 if the path doesn’t exist.
appendContentToFile: This allows the user to add content to a file. The function should take in the file path and the string content as input. If the file already exists, it appends the given content to the original content.
Example 1
Sample input
Q1: ["createFile", "/home/ben", "ben is a student"]Q2: ["getFileData", "home/ben"]
Sample output
["true", "ben is a student"]
Explanation
The first query creates a file home/ben and adds data ben is a student to it. Since the file was created successfully, true is returned as output. The second query fetches the data stored in the file and returns it.
Example 2
Sample input
Q1: ["createFile", "/home", "home directory"]Q2: ["createFile", "/home/ben", "Ben’s home directory"]Q3: ["createFile", "/home/ben/movies", "Ben’s favorite movies"]Q4: ["createFile", "/home/ben/college", "Ben’s college books"]Q5: ["createFile", "/home/ben/dance/videos", "Ben’s dance video"]Q6: ["getFileData", "/home/ben/dance/videos"]Q7: ["getFileData", "/home/ben/"]Q8: ["getFileData", "/home/ben/movies"]Q9: ["appendContentToFile", "/home/ben/movies", " includes Harry Potter"]Q10: ["getFileData", "/home/ben/movies"]
Sample output
[true, true, true, true, false, "-1", "Ben’s home directory", "Ben’s favorite movies",true, "Ben’s favorite movies includes Harry Potter"]
Explanation
Q1: ["createFile", "/home", "home directory"] => creates a file home and adds data home directory to it.
Q2: ["createFile", "/home/ben", "Ben’s home directory"] => creates a file ben under home directory and adds data Ben’s home directory to it.
Q3: ["createFile", "/home/ben/movies", "Ben’s favorite movies"] => creates a file movies under /home/ben directory and adds data Ben’s favorite movies to it.
Q4: ["createFile", "/home/ben/college", "Ben’s college books"] => creates a file college under /home/ben directory and adds data Ben’s college books to it.
Q5: ["createFile", "/home/ben/dance/videos", "Ben’s dance video"] => returns false as the parent path /home/ben/dance does not exist.
Q6: ["getFileData", "/home/ben/dance/videos"] => returns -1 as the file not present.
Q7: ["getFileData", "/home/ben/"] => returns the file contents (Ben’s home directory).
Q8: ["getFileData", "/home/ben/movies"] => returns the file contents (Ben’s favorite movies).
Q9: ["appendContentToFile", "/home/ben/movies", "includes Harry Potter"] => Adds to the content of the file and returns true. The final content becomes Ben’s favorite movies includes Harry Potter.
Q10: ["getFileData", "/home/ben/movies"] => returns the file contents (Ben’s favorite movies includes Harry Potter).
Try it yourself
Try to solve the problem yourself before reading the solution.
#include<iostream>#include<vector>using namespace std;class FileSystem {public:FileSystem() {}bool createFile(string path, string data) {// your code goes herereturn false;}bool appendContentToFile(string path, string newData) {// your code goes herereturn false;}string getFileData(string path) {// your code goes herereturn "";}};
Intuition
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