Beer and cookies for explanation... 😇

Question

Hello fellow sololearners! ☺
I was wandering if someone is willing to explain to me the logic behind this code that I got in a challenge. The best explanation gets free cookies and a beer from me 😉
Thank you in advance.

int[] pixels = new int[10000];
for (int y = 0; y < 100; y++) {
   for (int x = 0; x < 100; x++) {
index = x + y * 100;
pixels[index] = x + y;
   }
}
System.out.print(pixels[150]);

Correct answer by Sololearn is 51.

Answer 1

The only way to get pixels[150] is when y=1 and x=50. So y*100=100 + x=50 you get the array index of 150 and you store there x+y=50+1=51..

I hope it is clear

Answer 2

sure, beer's on me! here - 🍺
pm me when you come to Belgrade, I'll buy you a beer ;)
let me try to understand: the array location of 150 holds the value of 51, correct?
....
right, now i feel stupid 😄
I just saw it liks this:
150 = x + y*100
pixels = x + y
in our language this is called system of equations with two variables. real easy. hidden in code. damn it. :) thanks for the effort.

Answer 3

didn't look that easy during a challenge... 😠

Answer 4

do I get the beer?