Trapping of rainwater problem

Trapping of rainwater problem is a DSA topic. In plain words you use it for a short Trapping of rainwater problem example in a short dry-run on paper. Don’t start with a slogan — start with that picture.

Smallest example: the smallest Trapping of rainwater problem example you can type. Type it, run it, and say what you see. If you can do that from memory, you know Trapping of rainwater problem.

From the example next to this theory — Trapping of rainwater problem: dry-run [4, 1, 3].

Trap — only saying “Trapping of rainwater problem” with no example. Fix that before you talk about advanced DSA.

Viva: what is Trapping of rainwater problem? Then show the smallest Trapping of rainwater problem example you can type. Then name the trap.