C3E PUB_DATE: 2026.01.16

C3E: BENCHMARKING TIME-COMPLEXITY COMPLIANCE IN LLM-GENERATED CODE

JCST has a just-accepted paper proposing C3E, a benchmark to check whether LLM-generated code meets specified time-complexity constraints, not just functional c...

C3E: Benchmarking time-complexity compliance in LLM-generated code

JCST has a just-accepted paper proposing C3E, a benchmark to check whether LLM-generated code meets specified time-complexity constraints, not just functional correctness. This gives teams a way to detect algorithmic regressions when using AI coding assistants, especially for performance-sensitive backends and data pipelines.

[ WHY_IT_MATTERS ]
01.

Prevents hidden Big-O regressions when AI-generated code replaces optimized routines.

02.

Enables standardized comparison of models and prompt patterns against performance budgets.

[ WHAT_TO_TEST ]
  • terminal

    Add C3E-style tasks to your internal LLM eval harness with explicit complexity targets and verify outputs against input sizes.

  • terminal

    Gate AI-authored PRs by checking algorithmic complexity (e.g., via worst-case tests and input-scaling curves) before merging.

[ BROWNFIELD_PERSPECTIVE ]

Legacy codebase integration strategies...

  • 01.

    Integrate complexity checks into CI for hot paths and compare AI-generated alternatives against current baselines before rollout.

  • 02.

    Start with a narrow set of latency-critical endpoints or ETL kernels and expand once false positives/negatives are understood.

[ GREENFIELD_PERSPECTIVE ]

Fresh architecture paradigms...

  • 01.

    Define complexity budgets in coding guidelines for GenAI usage and include complexity assertions in test suites from day one.

  • 02.

    Curate a domain-specific task set (data transforms, joins, graph ops) with labeled complexity targets to steer prompts and model selection.