Bank Account with Cashback Rule | Dataford Interview Questions

Implement a bank account that supports deposit and withdraw operations. Withdrawals are more complex: 24 hours after a withdrawal, a cashback equal to 2% of the withdrawn amount is credited back, and the bank balance must be tracked/updated accordingly.

Asked in the online assessment stage. This was the only coding question among 12 total OA questions; the rest was non-coding and reported as difficult.

I/O Contract

Implement bank_account(initial_balance, operations). operations contains chronological [timestamp, type, amount] records, where type is "deposit" or "withdraw". Return the balance after each operation. Apply all cashback due at or before an operation's timestamp first. Reject withdrawals exceeding the current balance. Amounts are integer cents, and withdrawal amounts are divisible by 50.

Constraints

0 <= initial_balance <= 10^9
0 <= operations.length <= 1000
0 <= timestamp <= 10^9
Operations are sorted by nondecreasing timestamp
Each amount is a positive integer number of cents
Each withdrawal amount is divisible by 50
Operation type is either "deposit" or "withdraw"

Function Signature

def bank_account(initial_balance, operations):

Your question is Bank Account with Cashback Rule. 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