Company : Google
Location : Bangalore, India
Date of Interview : July 2nd, 2021

Telephoonic Phone Interview (45 min)
I was interviewed by a SWE from Google London.

Assume you're given the list of RequestType sent to the server on the previous day, implement the method which returns a random RequestType which has similar occurence to that of the list.

enum class RequestType { 1, 2 ,3 4 }

val observedRequest = List<RequestType>()

fun getRequestType() : RequestType {
	TODO()
}

For Example,

Input:
observedRequest  = [1,2,1,3,1,3]

Output:
requests = [1,2,1] or [1,1,3,3] or [1,2,2,1,3,3,1,3,3,1]

Explanation:
Accumulating the output from the getRequestType() should have similar occurences as that observedRequests. 
Here the frequency of RequestType are 1 = 1/3 , 2 = 1/6 , 3 = 1/3

Interview Experience:

I myself was confused with the question as I initially thought that this is similar to occurrences problem in LC. I suggested him I would convert the list to map -> [RequestType = Occurrence]. And then select the entries from map and then decrement the value.

The interviewer wanted the RequestType to be generated randomly which confused me further. I asked questions back to clarify myself but it rather confused me a lot. He then finally asked have you come across Random Generator in Java and how does it work. Asked what if you select a random value from list everytime. It satisfies the condition right? Can you now implement the method?

fun getRequestType() : RequestType{
	val random = Random()
	return observedRequest[random.nextInt()]
}

He then asked what if the random number exceeds the size and he himself corrected the code.

fun getRequestType() : RequestType{
	val random = Random()
	return observedRequest[random.nextInt(observedRequest.size)]
}

Then he said the above implementation same as

fun getRequestType() : RequestType{
	return observedRequest.random()
}

I told him I wasn;t sure whether I could use the in-built APIs. He added a follow up question as what if the list size is larger; say it's in millions or billions.

I then proposed we could makes use of the map and then select a random from it. He told ok. By then the time was over. He asked whether I have any questions.

I'm still waiting for the feedback. I think mostly I won't be able to make it for the onsite round. Or are there any chances?