Common Lisp · version 2

Run Common Lisp (SBCL) online

Common Lisp (SBCL) — run it in a Firecracker microVM on ls-judge. Real toolchain, no wrapper.

Starter code

What you get in Common Lisp (SBCL)

Clicking "Run now" opens the playground with this exact code and a matching test case — passes on first Run.

common lisp
Common Lisp (SBCL)
(let ((n (parse-integer (read-line))))
  (write-line (write-to-string (* n 2))))
stdin →21
expected →42
How it runs

How ls-judge runs Common Lisp (SBCL)

Every submission is compiled and executed inside its own Firecracker microVM — the same isolation primitive AWS Lambda uses. No shared container, no shared kernel with other users' code. The Common Lisp (SBCL)toolchain shipped with the microVM is the real thing (not a browser-side emulation): syscalls behave the way they do in production, and the compile / runtime behaviour matches what you would see on your own machine with that version installed.

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