Practice Coding Question | Real Coding Interviews

Quick Summary

Track a global collection of flagged PII values across a sequential event stream.
Classify underwriting events as suspicious if they share any previously flagged PII.
Propagate newly discovered PII from suspicious events into the tracking set for future checks.

What This Tests

Hash set operations for efficient membership testing
Stateful data structure design
Event-driven state transitions
Conditional update ordering

Common Patterns

Hashing

Design

An underwriting system receives customer events one at a time. Implement DistinctPIIValuesCounter to track the number of distinct PII (Personally Identifiable Information) values found across all underwriting events processed so far.

Each event is represented by a String[] with exactly five elements: [eventType, address, phone, email, ssn]. The address, phone, email, and ssn elements are PII fields.

Implement the DistinctPIIValuesCounter class:

DistinctPIIValuesCounter() initializes the counter with no recorded PII values.

Test Cases

Input

Output

Expected