LRU cache

qwen3-30b-a3b

Pythonagenticrun 2sample 0336.4s wall

← run 2 · raw JSON · challenge definitions

100

score

tests (60%)5/5 passed

deliverables (20%)100%

content checks (20%)100%

01 what the model was asked

Create lru.py with a class:

class LRUCache:
    def __init__(self, capacity: int)
    def get(self, key) -> value        # return the stored value, or -1 if absent
    def put(self, key, value) -> None  # insert or update

Semantics: the cache holds at most `capacity` entries. Both get() and put() count as a use of the key. When put() would exceed capacity, evict the least-recently-used key first. put() on an existing key updates its value and makes it most-recently-used.

Use only the Python standard library.

required deliverables + checks

✓deliverable: lru.py

✓lru.py must contain “class LRUCache”

✓lru.py must contain “def get”

✓lru.py must contain “def put”

pytest suite it was graded against

test_lru.py · 46 lines · 842 B

from lru import LRUCache  def test_basic_put_get():    c = LRUCache(2)    c.put("a", 1)    assert c.get("a") == 1    assert c.get("missing") == -1  def test_eviction_order():    c = LRUCache(2)    c.put("a", 1)    c.put("b", 2)    c.put("c", 3)    assert c.get("a") == -1    assert c.get("b") == 2    assert c.get("c") == 3  def test_get_refreshes_recency():    c = LRUCache(2)    c.put("a", 1)    c.put("b", 2)    c.get("a")    c.put("c", 3)    assert c.get("b") == -1    assert c.get("a") == 1  def test_put_overwrite_refreshes():    c = LRUCache(2)    c.put("a", 1)    c.put("b", 2)    c.put("a", 10)    c.put("c", 3)    assert c.get("b") == -1    assert c.get("a") == 10  def test_capacity_one():    c = LRUCache(1)    c.put("a", 1)    c.put("b", 2)    assert c.get("a") == -1    assert c.get("b") == 2

02 what it did — full transcript

write_fileturn 1 · lru.py · 590 B

run_teststurn 2 ·

✓ tests green5 passed

doneturn 3 ·

✓ done — gate green

graded 100.05 passed, 0 failed

pytest output

.....                                                                    [100%]
5 passed in 0.01s

03 what it wrote

files

lines

source lines

functions

classes

cyclomatic

max nesting

5.3

avg fn lines

stdlib imports: collections

File	LOC	SLOC	Fns	Complexity	Depth	Imports
lru.py	21	18	3	4	4	collections

lru.py · 21 lines · 590 B

from collections import OrderedDict class LRUCache:    def __init__(self, capacity: int):        self.capacity = capacity        self.cache = OrderedDict()     def get(self, key):        if key not in self.cache:            return -1        self.cache.move_to_end(key)        return self.cache[key]     def put(self, key, value):        if key in self.cache:            self.cache[key] = value            self.cache.move_to_end(key)        else:            self.cache[key] = value            if len(self.cache) > self.capacity:                self.cache.popitem(last=False)

04 how it was graded

✓ ok 5/5 passed

model calls

invalid actions

self test runs

3.5k

tokens out

—

tokens in

336.4s

wall time

agent actions: write_file×1, run_tests×1, done×1

final pytest output

.....                                                                    [100%]
5 passed in 0.01s