Implement hierarchical folder access check

You are asked to simulate a simple hierarchical file system and implement an access-check function.

The file system consists of folders arranged in a tree. A user is granted direct access to a subset of folders. Access is inherited down the tree: if the user has access to a parent folder, they automatically have access to all of its descendant folders.

You are given:

• A list of all folders in the system, represented as absolute paths from the root. For example, a tree like:

/
├── A
│   ├── B
│   │   ├── C
│   │   └── D
│   └── E
└── F

could be represented as:

allFolders = [
  "/",      
  "/A",
  "/A/B",
  "/A/B/C",
  "/A/B/D",
  "/A/E",
  "/F"
]

• A set of folder paths accessibleFolders representing folders to which the user has direct access. For example:

accessibleFolders = { "/A", "/F" }

You need to implement the function:

bool HasAccess(string folderPath)

that returns:

• true if the user has access to folderPath either because:
  • folderPath is in accessibleFolders , or
  • some ancestor folder of folderPath (e.g., /A is an ancestor of /A/B/C ) is in accessibleFolders .
• false otherwise.

Assume:

• All folder paths in allFolders and accessibleFolders are normalized absolute paths starting with '/' , with components separated by '/' (e.g., /A/B/C ).
• folderPath passed into HasAccess is always a valid folder path present in allFolders .

Examples (given the tree above and accessibleFolders = {"/A", "/F"}):

• HasAccess("/A") → true (direct access)
• HasAccess("/A/B") → true (inherits from /A )
• HasAccess("/A/B/C") → true (inherits from /A )
• HasAccess("/A/E") → true (inherits from /A )
• HasAccess("/F") → true (direct access)
• HasAccess("/") → false (no access to root unless / is in accessibleFolders )

Design and implement HasAccess so that it can be called many times efficiently after the initial inputs (allFolders and accessibleFolders) are known.