Skip to main content
mediumNeetCode 150

Walls and Gates

Walls and Gates is a traversal problem: the hard part is modeling the state you visit. Interviewers love it because it reveals your traversal modeling and your edge-case discipline. Be clear about what a state is; that's the difference between BFS/DFS working or blowing up.

Arrays & HashingGraphsBFS / DFS

Chat with Fin or Coco right now on mobile.

Start talking through the problem here. Switch to desktop when you're ready to code and run tests.

Start coaching session
Coco
Fin

Meet your coaches

Talk through the problem while you code. Guest text is free. Hosted voice is the Own Words Pack.

1Fill Distancesmedium

Code + tests need a desktop

Chat works on this phone. Email yourself a link when you want the editor and tests.