Bit Manipulation & Math
10 recent
Community-reported ยท source ยท updated 2026-10-08. โ asked in the last 6 months.
Go step by step: try it yourself before the video and the visual. Progress saves on this device.
Step 1
Know these before you start
Tick what you already know
Step 2
Try it on paper
5โ10 minutes, no code yet
About this problem
XOR tricks, bit counting, and matrix / number puzzles.
Read the full statement and examples on LeetCode, try it for 20โ30 minutes, then come back for the walkthrough and the step-by-step visual.
Step 6
Get it accepted
All test cases pass
Step 7
Review it so it sticks
Re-solve from memory after
Three lines in your own words. They come back with this problem's reviews, so you can check yourself after recalling the solution.
Reading the solution first feels like progress, but it makes the next similar problem โ and the interview version โ much harder, because you skipped the part where you figure it out. Give it an honest 20โ30 minutes. Stuck? Re-read the pattern, watch the concept video, or try the brute force first.
Hidden: optimal solution