Process Banking Operations
Vercel● MediumFULLTIMEOAProblem statement
Maintain account balances while processing a finite ordered list of banking operations. Each operation is a string array.
["CREATE", account]creates an account with balance zero and returns1, or returns0if it already exists.["DEPOSIT", account, amount]adds a positive amount and returns the new balance, or-1for an unknown account.["TRANSFER", from, to, amount]moves a positive amount between distinct accounts and returns the source account's new balance, or-1if either account is unknown, the accounts are equal, or the source lacks funds.["BALANCE", account]returns the current balance, or-1for an unknown account.
Return one integer result per operation in input order. A rejected operation does not change any balance.
Function
processBankingOperations(operations: String[][]) → long[]Examples
Example 1
operations = [["CREATE","alice"],["DEPOSIT","alice","20"],["BALANCE","alice"]]return = [1,20,20]The operations create one account, deposit funds, and read its balance in order.
Example 2
operations = [["CREATE","a"],["CREATE","b"],["DEPOSIT","a","9"],["TRANSFER","a","b","4"],["TRANSFER","a","b","8"],["BALANCE","b"]]return = [1,1,9,5,-1,4]The successful transfer leaves five in a and four in b; the next transfer is rejected without mutation.
Constraints
1 <= operations.length <= 100000- Account names are nonempty strings of letters and digits with length at most
40. - Transaction amounts are decimal integers between
1and1000000000. - Every balance fits signed 64-bit arithmetic.
- Each operation has exactly the fields described above.