Hello, Modulo

Who needs modulo when you have bitwise NOT? (⌐■_■)

← 02-intro-challenges-1

#1 on both code size AND cycles leaderboards!

Grid	Code Size	Leaderboard	Cycles	Leaderboard	Date
13x13x13	5	🏆 #1	4.000	🏆 #1	2026-02-23

Solution

return~x&1

How it works

The puzzle wants vertical slabs at every even x. The textbook approach is x%2==0 (6 tokens), but bitwise is cheaper. ~x flips every bit, then &1 isolates the last one. Even numbers have bit 0 = 0, which flips to 1 (WHITE). Odd numbers have bit 0 = 1, which flips to 0 (empty). Five tokens, four cycles, nowhere left to go.