Hello Codeforces!

I wanted to share a tool I’ve been building for competitive programming:

https://cptoolapp.web.app/

CP Tool is a free web app that runs directly in the browser. There is no login, no setup, and no backend server needed for the actual tools. Just open the site and use it.

What it currently includes:

• Interactive graph editor
• Graph parsing from common input formats
• Algorithm visualization/playback for things like BFS, Dijkstra, MST, SCC, topological sort, bridges/articulation points, tree diameter, LCA, subtree size, etc.
• CP calculators for number theory, combinatorics, bit operations, matrices, and strings String algorithm helpers like KMP, Z-function, rolling hash, Manacher, trie, Aho-Corasick, suffix array, and suffix automaton
• Grid/coordinate helper for geometry-style and compressed-grid problems
• Curated CP resources: platforms, practice ladders, references, tools, and communities
• Documentation inside the app

The idea is not to replace your editor or online judge. It is more of a small workbench for understanding, debugging, and visualizing ideas while practicing or upsolving.

Some use cases:

• Paste a graph and quickly check how an algorithm behaves
• Visualize graph traversal or shortest paths
• Test small number theory / combinatorics values
• Inspect string algorithm outputs without writing a quick script every time
• Draw or reason about grid/coordinate inputs
• Keep useful CP links in one place

I would really appreciate feedback from the community, especially on:

• Which algorithms would be most useful to add next?
• Which graph input formats should be supported?
• What calculators or visualizers do you usually wish existed during practice?
• Any UI/UX issues you notice while using it? Link again:

https://cptoolapp.web.app/

Thanks, and I hope it helps someone during practice or upsolving.