> ## Documentation Index
> Fetch the complete documentation index at: https://leetcode-py.wisl.dev/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> leetcode-py is a Python LeetCode practice environment generator with one CLI: lcpy. It is not a service or platform.
> Each problem is a directory under leetcode/ with README.md, solution.py, test_solution.py, helpers.py, and playground.ipynb. lcpy gen creates them from JSON templates bundled with the package.
> Examples are backed by tests; copy them verbatim.

# Visualizations Show ASCII Instead of Diagrams

> Data structure visualizations print as ASCII text instead of diagrams when the system Graphviz binary is missing. Install Graphviz and restart the terminal.

No error is raised. Visualization objects print as ASCII fallback text
instead of rendered diagrams, which means the system Graphviz binary is
missing. The Python package alone is not enough: rendering shells out to
the `dot` executable.

## Fix

Install Graphviz for your platform
([download guide](https://graphviz.org/download/)):

```bash theme={"theme":{"light":"github-light","dark":"github-dark"}}
brew install graphviz      # macOS
sudo apt install graphviz  # Debian/Ubuntu
```

Restart the terminal afterwards so the new binary is on `PATH`, then
re-run the notebook or script. What the rendered output looks like is
shown in [Visualizations](/practice/visualizations).

Not this problem? Every fix lives on
[Troubleshooting](/troubleshooting).