Cloud Storage File Versioning

Implement an in-memory cloud storage system that keeps every version of an overwritten file. Process the operations in order and return one string result per operation.
File Operations
["ADD_FILE", file_name, size]: create a file and return created. If the name already exists, append a new version with the supplied size and return overwritten. Versions are numbered from 1.
["GET_FILE_SIZE", file_name]: return the latest version's size, or an empty string if the file does not exist.
["MOVE_FILE", name_from, name_to]: move the file and all of its versions. Return false if the source is missing or the destination already exists; otherwise return true.
["GET_LARGEST_N", prefix, n]: return up to n prefix-matching files, using each file's latest size. Sort by size descending and file name ascending; format as name(size), name(size). Return an empty string when no file matches.
Version Operations
["GET_VERSION", file_name, version]: return that version's size, or an empty string if the file or version does not exist.
["DELETE_VERSION", file_name, version]: permanently delete that version and return true. Return false when it does not exist.
After deletion, every higher version number decreases by one. Deleting a file's only version permanently removes the file.

Function
cloudStorageFileVersioning(operations: String[][]) → String[]

Examples
Example 1
operations = [["ADD_FILE","/file-a.txt","6"],["ADD_FILE","/file-a.txt","3"],["GET_VERSION","/file-a.txt","2"],["GET_VERSION","/file-a.txt","4"],["GET_VERSION","/file-a.txt","1"],["DELETE_VERSION","/file-a.txt","1"],["GET_VERSION","/file-a.txt","1"]]
return = ["created","overwritten","3","","6","true","3"]
The second write creates version 2. Deleting version 1 renumbers the former version 2 to version 1.

Constraints
All integer parameters are between 1 and 200.

Store each file as a name mapped to an ordered list of sizes. Version k is index k-1, so renumbering after a delete comes free: remove the element and everything after it shifts down. That's the trick. Don't store explicit version numbers, or you'll be rewriting them on every delete. ADD_FILE appends to the list. GET_FILE_SIZE reads the last element. MOVE_FILE moves the whole list under a new key, after checking the source exists and the destination doesn't. Deleting the only version must remove the key entirely, or a later ADD_FILE returns overwritten instead of created. GET_LARGEST_N filters by prefix, sorts by latest size descending then name ascending, takes n, and formats as name(size). Return an empty string when nothing matches. Constraints are tiny, so a full scan per query is fine. If the edge cases tangle on the live OA, StealthCoder is your hedge.

The honest play: practice the pattern, and have StealthCoder ready for the one you didn't see coming.