cpp.md

C++ and your language server

Starter code for C++ has no #includes, no using namespace std;, and no definition of ListNode / TreeNode / Node / Interval. The judge supplies all of it implicitly. A language server does not, so a perfectly valid solution lights up red.

Rather than editing your solution, the plugin writes a .clangd next to your solutions directory. It is on by default; runner.cpp.clangd = false turns it off.

What gets written

solutions/
├── .clangd                 # one fragment per problem, PathMatch-scoped
└── .meatcode/
    ├── prelude.h           # standard library + using namespace std
    ├── clone-graph.h       # class Node { vector<Node*> neighbors; ... }
    └── meeting-schedule.h  # class Interval { int start, end; ... }

The config force-includes prelude.h for every solution, plus a per-problem header holding that problem's own helper types, lifted from the definition NeetCode leaves in its starter comment.

Per-problem rather than shared, because there is no single right answer: Node is an adjacency list in Clone Graph and a random pointer in Copy List with Random Pointer. Each problem gets the one it actually has, so node->random is correctly rejected in Clone Graph instead of quietly accepted.

Compile flags — including -std — are taken from runner.cpp.cmd, so clangd parses your file in the same language mode the local runner compiles it in.

Guarantees

• Your solution file is left exactly as the provider wrote it. Nothing is inserted into it and nothing extra is submitted.
• Headers are written when you open a problem, and .clangd is rebuilt from whatever headers exist on disk, so the two never drift.
• A .clangd the plugin did not write is left alone only if it already matches runner.cpp.cmd (same -std / -stdlib). A stale or conflicting one is overwritten.

Measured over seeded solutions, clangd --check goes from 1–4 errors per file to zero.