25-make-a-spiral.md

Problem:

Your task, is to create a NxN spiral with a given size.

For example, spiral with size 5 should look like this:

00000
....0
000.0
0...0
00000

and with the size 10:

0000000000
.........0
00000000.0
0......0.0
0.0000.0.0
0.0..0.0.0
0.0....0.0
0.000000.0
0........0
0000000000

Return value should contain array of arrays, of 0 and 1, for example for given size 5 result should be:

[[1,1,1,1,1],[0,0,0,0,1],[1,1,1,0,1],[1,0,0,0,1],[1,1,1,1,1]]

Because of the edge-cases for tiny spirals, the size will be at least 5.

General rule-of-a-thumb is, that the snake made with '1' cannot touch to itself.

Solution