Efficient Logic Coding Challenge | Dataford Interview Questions

Your question is Efficient Logic Coding Challenge. Start with the requirements on the right.

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

Problem

A Google Cloud Dataflow worker receives an ordered list of event labels. Given events and a set of required labels, return the shortest contiguous range of events that contains every required label at least once.

Return the range as [start, end], using inclusive zero-based indices. If no range contains all required labels, return [-1, -1]. If multiple ranges have the same minimum length, return the one with the smallest starting index.

Formal Specification

Input: events, a list of strings, and required, a list of distinct strings.
Output: A two-element list [start, end] of integers, or [-1, -1] when no valid range exists.
A valid range must contain every string in required at least once.

Constraints

1 <= len(events) <= 10^5
1 <= len(required) <= 10^4
Each event label is a non-empty string of length at most 50
required contains distinct labels
Return the earliest range when multiple minimum-length ranges exist

Function Signature

def minimum_event_window(events, required):

Your question is Efficient Logic Coding Challenge. Start with the requirements on the right.

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

Formal Specification

Input: events, a list of strings, and required, a list of distinct strings.
Output: A two-element list [start, end] of integers, or [-1, -1] when no valid range exists.
A valid range must contain every string in required at least once.

Constraints

1 <= len(events) <= 10^5
1 <= len(required) <= 10^4
Each event label is a non-empty string of length at most 50
required contains distinct labels
Return the earliest range when multiple minimum-length ranges exist

Function Signature

def minimum_event_window(events, required):