Permission System With Trees | Dataford Interview Questions

How would you design a permission system using a tree data structure?

Implement permission_queries(parent, permissions, operations). parent maps each node to its parent, with the root mapped to None. permissions[node][principal][action] is either "allow" or "deny". Operations are ['grant', node, principal, action], ['revoke', node, principal, action], or ['check', node, principal, action]. A permission is inherited from ancestors, and the closest explicit rule wins. Return booleans for check operations in order.

Constraints: the structure is a valid rooted tree, node depth is at most 5,000, and there are at most 5,000 operations. Actions and principals are non-empty strings.

Constraints

parent describes a valid rooted tree with 1 to 5,000 nodes
The root is the only node whose parent is None
Every operation references an existing node
There are 1 to 5,000 operations
Each operation is a list of four strings
Each permission value is either "allow" or "deny"
A missing rule defaults to deny

Function Signature

def permission_queries(parent, permissions, operations):

Your question is Permission System With Trees. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

How would you design a permission system using a tree data structure?

Constraints: the structure is a valid rooted tree, node depth is at most 5,000, and there are at most 5,000 operations. Actions and principals are non-empty strings.

Constraints

parent describes a valid rooted tree with 1 to 5,000 nodes
The root is the only node whose parent is None
Every operation references an existing node
There are 1 to 5,000 operations
Each operation is a list of four strings
Each permission value is either "allow" or "deny"
A missing rule defaults to deny

Function Signature

def permission_queries(parent, permissions, operations):

Your question is Permission System With Trees. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.