Question

I have an assignment where I have questions that ask for the following implementations:

insertAtRanks(Integer x, Integer y, Object o): insert a new element to be stored at position (x,y) 

and

Object removeAtRanks(Integer x, Integer y): remove and return the element at position (x,y)

It already asked for the implementation of replaceAtRanks where I had to replace the element inside a position with a parameter.

So what I assume when inserting and removing elements, the matrix will increase and decrease in size, but my question is how?

For example

| 3    6|
| 2    5|

If I had to do an insert number 8 at position (1,1) will the following happen?

| 3    6|
| 2    8|
| null 5|

And if I had to remove the element at (1,1) afterwards will it go back to?

| 3   6|
| 2   5|

Edit:

I am using Java for the implementation, and I am using a 2 dimensional array of classes to represent the matrix.

Answer 1

|3    6|
|null 8|
|2    5|

or

|3    6|
|0    8|
|2    5|

or

|3    6|
|2    8|

or many other forms suggest themselves as alternatives. I think you have to decide what you have been asked to implement, and then implement it.