Big O

Question 1

O(1)

Answer 1

Constant time

Question 2

Types of 0(1) operations

Answer 2

Array access by index
Math
Hash by key
Pushing, popping on stack
Insertion and removal from queue
Return value from function

Question 3

O(n)

Answer 3

Linear increase with size of dataset
Map, reduce,
Looping through something etc

Question 4

O(n^2)

Answer 4

Quadratic time

• nested loops
• bubble sort and other simple sort algorithms

Question 5

O(n log n)

Answer 5

Linearithmic
Merge sort
Timsort
Heapsort

Question 6

Call stack

Answer 6

Responsible for keeping the flow of execution

Question 7

Heap

Answer 7

Memory allocation accessible by all threads

Question 8

Young generation

Answer 8

It’s the portion of the memory where all the new data(objects) are made to allocate the space and whenever this memory is completely filled then the rest of the data is stored in Garbage collection.

Question 9

Old/Tenured generation

Answer 9

This is the part of Heap-memory that contains the older data objects that are not in frequent use or not in use at all are placed.

Question 10

Permanent generation

Answer 10

This is the portion of Heap-memory that contains the JVM’s metadata for the runtime classes and application methods.