Nice. That's why you should consider to learn some math to become a better programmer. ;)

lmao

This shouldn't pass the tests. The index calculation in [r%3/3+c/3][r/3*3+c%3] is incorrect.

It sometimes fails the random tests (probability ca. 10%). The fixed tests are too lenient.

Stumbled upon here, that > 0 in while (len-- > 0) is not needed, the loop will finish without (a 0 will be a false), and I like it.

this shit is bad yo, seriously. You people dont work with others peoples code? lisibility over stupid reduced fonctions

Nice I done almost the same but used
sb when read from array.

// while (len --> 0)
while (len-- > 0)

Space input position changed, almost can't recognize

God love whoever voted this a best practise :D

Ow... I think i see...

Wtf! How this works?

... this... okay, not bad.

But... can you make it have more black magic? Like... with pointer maths?

Ah, you are right, but I expect this to crash if z appears. Next time I'll use just [26] :). TY for let me know

'z' - 'a' gives 25, but there is 26 letters, hence function returns false if z letter appears;
if string contains two+ capital letters function returns false;