How should I practice Ordered IP Firewall?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Databricks phone screen problems in FastPrep.

Is Ordered IP Firewall associated with Databricks?

FastPrep tags this as a Databricks phone screen coding practice problem when the problem catalog has that company and stage context.

Problem · Array

Ordered IP Firewall

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Problem statement

You are given an ordered IPv4 firewall. Rule i has action actions[i], which is either "ALLOW" or "DENY", and target cidrs[i], which is either one IPv4 address or an IPv4 CIDR network.

Evaluate the query address against the rules in order. A plain address matches only itself. A CIDR target a.b.c.d/p matches exactly the addresses whose first p bits equal the target network's first p bits. Return true for the first matching ALLOW rule and false for the first matching DENY rule.

Function

allowAccess(actions: String[], cidrs: String[], ip: String) → boolean

Examples

Example 1

actions = ["DENY","ALLOW"]cidrs = ["10.0.0.0/8","0.0.0.0/0"]ip = "10.4.5.6"return = false

The address is inside 10.0.0.0/8, so the first rule matches and denies access.

Example 2

actions = ["ALLOW","DENY","ALLOW"]cidrs = ["192.168.1.9","192.168.1.0/24","0.0.0.0/0"]ip = "192.168.1.9"return = true

The exact-address rule appears before the broader deny rule, so its allow decision wins.

Constraints

1 <= actions.length = cidrs.length <= 200000.
Every action is "ALLOW" or "DENY".
Every target and query is a valid dotted-decimal IPv4 address; a CIDR prefix is between 0 and 32.
At least one rule matches the query.