Design Simple File System

Problem Statement

Design a basic file system that offers two operations:

• addPath(route, val): Creates a new path with an associated integer value if it doesn't exist and its parent path exists. Returns true if successful, otherwise false.
• fetch(route): Returns the integer value linked with the given path. Returns -1 if the path is not found.

A valid path consists of one or more segments starting with a slash / followed by lowercase letters. For example, /example and /example/test are valid paths, while an empty string or / alone are invalid.

Implement these two methods to manage the file system.

Examples

addPath("/x", 5)  // returns true
fetch("/x")       // returns 5
    

addPath("/abc", 3)       // returns true
addPath("/abc/def", 7)   // returns true
fetch("/abc/def")        // returns 7
addPath("/xyz/123", 10)  // returns false (parent path "/xyz" does not exist)
fetch("/xyz")            // returns -1
    

Constraints

• Number of calls to addPath and fetch will not exceed 12,000 in total.
• Path length is between 3 and 110 characters inclusive.
• Value associated with a path is between 1 and 10⁹ inclusive.