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O(1) LRU cache with correct eviction

One task across 30 published runs. Inspect the scores and outputs together, with each run's execution method shown.

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Task
CODE-0003
Domain
Programming
Difficulty
medium

Leading published run: claude-opus-4-8 (low reasoning) at 100.0% composite. Lowest: claude-haiku-4-5 at 0.0%. 30 published runs shown on this task.

How this task was evaluated

Results are ordered by this task's published score. API runs use one prompt and one completion; agent runs use a coding harness with tools and iteration. Inspect the execution method when comparing results.

Objective scores use the benchmark's execution checks. Judge scores use a vision panel's fixed rubric; the published score leaves out a model's own family. Missing values are labelled rather than treated as zero.

Read the brief

Implement a Python class `LRUCache` (a least-recently-used cache) with these methods, each running in O(1) average time: - `LRUCache(capacity)`: construct an empty cache that holds at most `capacity` keys. `capacity` is a non-negative integer. - `get(key)`: return the value for `key`, or -1 if the key is not present. A successful get marks the key as the most recently used. - `put(key, value)`: insert or update the value for `key`, and mark it as the most recently used. If this makes the cache exceed `capacity`, evict the least recently used key first. Edge cases that matter: - A `get` counts as a use: it must refresh the key's recency. - Updating an existing key with `put` also refreshes its recency and must not grow the cache. - `capacity == 0` stores nothing: every `put` is a no-op and `get` always returns -1. Use only the Python standard library. Write your solution to `solution.py`.

Anthropicclaude-opus-4-8
Low reasoning
Agent harness2026-07-21
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-opus-4-8
Medium reasoning
Agent harness2026-07-21
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-opus-4-8
Extra-high reasoning
Agent harness2026-07-21
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-opus-4-8
Max reasoning
Agent harness2026-07-21
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-sonnet-4-6
High reasoning
Agent harness2026-07-21
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-sonnet-5
High reasoning
Agent harness2026-07-21
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-fable-5
High reasoning
Agent harness2026-07-09
Composite 100.0%Objective 100.0%
Open outputFull run
Zhipuglm-5.2
default reasoning
API single-shot2026-07-17
Composite 100.0%Objective 100.0%
Open outputFull run
Moonshotkimi-k2.7-code
default reasoning
API single-shot2026-07-17
Composite 100.0%Objective 100.0%
Open outputFull run
Moonshotkimi-k3
default reasoning
API single-shot2026-07-17
Composite 100.0%Objective 100.0%
Open outputFull run
OpenAIgpt-5.5
High reasoning
API single-shot2026-07-17
Composite 100.0%Objective 100.0%
Open outputFull run
OpenAIgpt-5.4-mini
High reasoning
API single-shot2026-06-23
Composite 100.0%Objective 100.0%
Open outputFull run
OpenAIgpt-5.6-sol
High reasoning
API single-shot2026-07-09
Composite 100.0%Objective 100.0%
Open outputFull run
OpenAIgpt-5.6-sol
Max reasoning
API single-shot2026-07-09
Composite 100.0%Objective 100.0%
Open outputFull run
OpenAIgpt-5.6-terra
High reasoning
API single-shot2026-07-09
Composite 100.0%Objective 100.0%
Open outputFull run
OpenAIgpt-5.6-luna
High reasoning
API single-shot2026-07-09
Composite 100.0%Objective 100.0%
Open outputFull run
Googlegemini-3.1-pro-preview
High reasoning
API single-shot2026-06-23
Composite 100.0%Objective 100.0%
Open outputFull run
Googlegemini-3.5-flash
default reasoning
API single-shot2026-06-23
Composite 100.0%Objective 100.0%
Open outputFull run
Googlegemini-3.1-flash-lite
default reasoning
API single-shot2026-06-23
Composite 100.0%Objective 100.0%
Open outputFull run
xAIgrok-4.5
High reasoning
API single-shot2026-07-09
Composite 100.0%Objective 100.0%
Open outputFull run
xAIgrok-4.5
Medium reasoning
API single-shot2026-07-09
Composite 100.0%Objective 100.0%
Open outputFull run
xAIgrok-4.5
Low reasoning
API single-shot2026-07-09
Composite 100.0%Objective 100.0%
Open outputFull run
xAIgrok-4.3
default reasoning
API single-shot2026-07-03
Composite 100.0%Objective 100.0%
Open outputFull run
xAIgrok-4.20-reasoning
default reasoning
API single-shot2026-06-25
Composite 100.0%Objective 100.0%
Open outputFull run
xAIgrok-build-0.1
default reasoning
API single-shot2026-06-25
Composite 100.0%Objective 100.0%
Open outputFull run
xAIgrok-composer-2.5-fast
default reasoning
Agent harness2026-06-25
Composite 100.0%Objective 100.0%
Open outputFull run
DeepSeekdeepseek-v4-pro
default reasoning
API single-shot2026-06-25
Composite 100.0%Objective 100.0%
Open outputFull run
DeepSeekdeepseek-v4-flash
default reasoning
API single-shot2026-06-25
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-opus-4-8
High reasoning
Agent harness2026-07-21
Composite 0.0%Objective 0.0%
Open outputFull run
Anthropicclaude-haiku-4-5
High reasoning
Agent harness2026-07-09
Composite 0.0%Objective 0.0%
Open outputFull run

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