Detect Transaction Anomalies | Dataford Interview Questions

Write a function to detect transaction anomalies within a highly active database log.

Each record is [timestamp, transaction_id, event, amount]. Events are BEGIN, WRITE, COMMIT, or ABORT; BEGIN.amount is the expected total and COMMIT.amount is the reported total. Return sorted transaction IDs whose lifecycle is invalid, whose committed amount does not equal the expected amount and sum of writes, or that remain unfinished. Preserve input order when processing records.

Signature: def detect_transaction_anomalies(log):

Constraints

1 <= len(log) <= 200000
Each record has the form [timestamp, transaction_id, event, amount]
timestamp is an integer and records are provided in processing order
transaction_id is a non-empty string
event is one of BEGIN, WRITE, COMMIT, or ABORT
amount is an integer
The number of distinct transaction IDs is at most len(log)

Function Signature

def detect_transaction_anomalies(log):

Your question is Detect Transaction Anomalies. 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

Write a function to detect transaction anomalies within a highly active database log.

Signature: def detect_transaction_anomalies(log):

Constraints

1 <= len(log) <= 200000
Each record has the form [timestamp, transaction_id, event, amount]
timestamp is an integer and records are provided in processing order
transaction_id is a non-empty string
event is one of BEGIN, WRITE, COMMIT, or ABORT
amount is an integer
The number of distinct transaction IDs is at most len(log)

Function Signature

def detect_transaction_anomalies(log):

Your question is Detect Transaction Anomalies. 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.