I have appeared for google interview.
1 st round- screening round
2nd round - coding round
they asked me this question in 2nd round
Imagine you have a robot that sends status messages that humans will read in real time.
The raw messages are hard to read for a human because there are often many messages produced in short periods of time.
One idea to make them more readable is to remove the duplicate messages over a 10 second window.
Design and implement a program to hide duplicates of any message that has already been displayed within the past 10 seconds.

Example Messages Received, with Timestamps:
10 solar panel activated
11 low battery warning
12 tire one: low air pressure
13 solar panel activated
14 low battery warning
21 solar panel activated
35 solar panel activated

Example Messages Shown to User:
10 solar panel activated
11 low battery warning
12 tire one: low air pressure
21 solar panel activated
35 solar panel activated
it was a easy problem but i was trying to give approach only. but didn't write the code as interviewer was not okay with approach.
it was a easy HashMap question where we just need to store message as key and timestamp as value.
if msg is not present in hashmap return true and print the message and store the message in hashmap
and then
find lasttimestamp of that message in HashMap , if timestamp-lasttimestamp> threshold time then return true and print the msg and store the msg else return false and not store message.
I was cleared with this, but interviwer didn't ask to write code.
and may be i lost the opportunity this time.
Because i didn't write code. lets see what will be result.