Speed Perf Throughput Data Structures

The model receives the prompt (and optional system message). The run uses scorer contains_all with the JSON configuration below. Pass/fail and partial credit are determined entirely by that scorer against the model output; no human grading.

Write an in-depth technical explanation of a least-recently-used (LRU) cache suitable for senior engineer interview prep. Requirements:
- Use exactly these headings in order: ## Motivation ## Structure ## Operations ## Complexity
- Include step-by-step Python-like pseudocode for get and put
- Discuss why combining a hash map with a doubly linked list achieves typical O(1) operations
- Write multiple paragraphs per section; be exhaustive, not terse.

Write in English.

{
  "expected_contains": [
    "## Motivation",
    "## Complexity",
    "LRU",
    "O(1)",
    "hash"
  ]
}