Why would you want to _not_ use a map? You would be using bad development patterns and over complicating code. You also risk creating runtime errors by attempting to update an Account multiple times if you use a list of Accounts. A Map of Accounts by Account Id, like a Set, is a good design practice to deduplicate values when used correctly.
Please try below code:
PLease let me know if helped.
Regards,
Ramakant
Is there any way to implement this trigger without using map.