Find the hidden message in... this grid

Question

(So I made this puzzle, and I wanted it to be fun rather than difficult! I hope it’s original enough)

Given a 5x5 grid as input, here’s an algorithm:

• randomly select any 3x3 grid within the 5x5 grid
• randomly select a number
• add that number to all numbers within the 3x3 grid
• repeat for a random amount of times

Now here are two grids:

Grid A:

39174	39174	85267	46093	46093
39174	39174	85267	46093	46093
102625	102625	219841	117216	117216
63451	63451	134574	71123	71123
63451	63451	134574	71123	71123

Grid B:

53329798	53329798	116037282	62695584	62695584
53329798	53329798	116037282	62695584	62695584
106466735	106466735	219003633	112558698	112558698
53125437	53125437	102987951	49852814	49852814
53125437	53125437	102987951	49852814	49852814

Question 1: if grid A is given as input to the algorithm above, is grid B a possible output?

Question 2: in the process of finding an answer to question 1, you should find a set of numbers. But that is not just any set! A specific permutation of this set can be translated into a piece of ASCII text. But that is not just any piece of ASCII text! It is the code that can unlock the meaning of life! Find that code, and enlighten the masses!

Hint:

if you found a somewhat obvious selection of numbers that can’t be translated to ASCII or utilized otherwise, you either found the wrong selection of numbers, or you will have to perform a somewhat obvious modification on those numbers (for example if you come across the number "444444" and you think it’s too long, you could try removing some digits from that number, since the digit "4" is very clearly a pattern there).

Answer 1

The only things that actually matter

are the total amounts you add to each of the nine possible square positions. (Adding 3 top the top-left square, then doing some other stuff, then adding 5 to the top-left square, is just the same as adding 8 to the top-left square and doing that other stuff -- that is, the order doesn't matter.)

In addition, the starting values don't matter - you can just subtract them away from the ending values. So it's easy to do the calculations:


The left grid here shows the "areas of influence" of 3×3s centered on points a and f. The right grid shows the total values of each of the numbers once you've subtracted away the starting values.

But it's actually even easier than that in this particular case:

The subtraction shows that you only chose the four corner grids, and so it's easy to read off the total amounts each were modified by.

You only actually chose the corner 3×3s. Since each of those is the only one to hit its corresponding corner, the adjustments can just be read off directly from the difference between the grids.

But the edge numbers don't add up to the right amounts, then - so it's not possible. Specifically, the top two are off by 11900, the bottom two by 9700, the left two by 11500, and the right two by 10300.

Dividing each of these by 100 and converting to ASCII, they read swag (in the order ←↑↓→).