Balance Calculation and Rejected Transactions

Given a list of transactions, output all users with a non-zero balance and their balances. Then output transactions that would cause a balance to be negative in a rejected transaction list and again output users with a non-zero balance and their balances. Example input: account_name, timestamp, currency, amount acct_123,1,usd,1000 acct_123,2,usd,500 acct_321,3,usd,400 acct_321,4,usd,-500 Example output: acct_321 and 1500, acct_312 and 400, rejected_transaction = ["acct_321,4,usd,-500"] Example Input account_name, timestamp, currency, amount acct_123,1,usd,1000 acct_123,2,usd,500 acct_321,3,usd,400 acct_321,4,usd,-500