My solutions to a set of server programming challenges published here: https://protohackers.com/
The grader here seems to be very lax, according to the problem description we might get an input like 1.3e1 to which we'd obviously have to return true, but such an input never occurs.
Sum is biiig
Be careful to not inform a user about events that happened after the user connected but before they fully joined.
Don't strip newlines!
Don't get confused by reading the messages sent by the tester. One message reads "7PBqhi52gBQukUuL4EUegLYQHW is too short", yet the address is valid and should be replaced.