Java map vs flatmap interview questions

Описание: Java map vs flatmap interview question?

1. Given a List of integers, return a List which contains square of those numbers. For example, input list is 1, 2, 3, 4, 5, 6 then you should return a list containing 1, 4, 9, 16, 25, 36,
This is simple, we just need to use list on list call Stream method, on stream method call, map method, inside map method write lamba expression like this,
x - x*x, we just multiplying inside map method. Once done,