> For the complete documentation index, see [llms.txt](https://programming.arora-aditya.com/leetcode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://programming.arora-aditya.com/leetcode/design.md).

# Design

- [251. Flatten 2D Vector](https://programming.arora-aditya.com/leetcode/design/251.-flatten-2d-vector.md)
- [281. Zigzag Iterator](https://programming.arora-aditya.com/leetcode/design/281.-zigzag-iterator.md)