SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

lru-cache

claude-code claude-haiku-4-5 ✓ resolved GOOD_SUCCESS 13 turns · 42 tok in · 20,773 tok out ↑ View task
Solved from the instruction alone, tests/ and solution/ were withheld from the agent's workspace and restored only for grading.
Reward = tests/test.sh exit code (0 → resolved); the classification below is post-hoc and cannot change it.
Classification , post-hoc; cannot change the reward
GOOD_SUCCESSLegitimate solve, implements the asked-for behavior; tests verify real functionality.
SubtypeLegitimate Solution
EvidenceAgent passed all 13 pytest tests including: test_output_exists, test_shipped_input_correct, test_shipped_exercises_the_gate, test_shipped_invariants, and 8 parametrized test_hidden_inputs[seed] tests with seeds [3,4,8,11,13,16,33,47]. Result shows correct get_results=[100,200,100,300,100,200,-1,400,100,200,-1,800,-1], final_probation=[[2,200]], final_protected=[[1,150],[8,800]], total_weight=5, rejected=2. Agent trajectory shows systematic implementation of cache simulator with OrderedDict for recency ordering, correct expiry sweep logic, frequency aging, two-segment promotion/demotion, and frequency-gated admission. Agent manually verified correctness via debug traces.
Root causeAgent successfully implemented a complex cache simulator by carefully reading the detailed specification, understanding all interacting rules (logical clock, weight budgets, frequency gates, segment management), and implementing robust logic that passes both the shipped test and 8 anti-hardcoding hidden tests with varying parameters.
RecommendationN/A - task is fine
Trajectory
Tool-by-tool agent trajectory
12 tool calls · 3 tool types · 24 steps
Looking at this cache simulation task, I need to implement a sophisticated two-segment cache with frequency gates, expiry-based invalidation, and weight-based eviction. Let me build this step by step.

<tmp>/workspace

contents
EISDIR: illegal operation on a directory, read '<tmp>/workspace'
Let me check the structure first.
shell
ls -la <tmp>/workspace
output
total 40
drwxr-xr-x  7 jaykumar  staff   224 17 Jun 15:34 .
drwx------  4 jaykumar  staff   128 17 Jun 15:34 ..
drwxr-xr-x  3 jaykumar  staff    96 17 Jun 14:36 data
drwxr-xr-x  3 jaykumar  staff    96 17 Jun 14:36 environment
-rw-r--r--  1 jaykumar  staff  9746 17 Jun 14:36 instruction.md
-rw-r--r--  1 jaykumar  staff  1049 17 Jun 14:36 main.py
-rw-r--r--  1 jaykumar  staff   323 17 Jun 14:36 task.toml
Now let me read the data file and existing main.py:

<tmp>/workspace/data/operations.json

contents
1	{
2	  "capacity": 9,
3	  "protected_capacity": 4,
4	  "default_ttl": 8,
5	  "miss": -1,
6	  "reset_interval": 7,
7	  "operations": [
8	    ["put", 1, 100, 2],
9	    ["put", 2, 200, 2],
10	    ["put", 3, 300, 1],
11	    ["get", 1],
12	    ["get", 2],
13	    ["get", 1],
14	    ["put", 4, 400, 2],
15	    ["get", 3],
16	    ["get", 1],
17	    ["put", 5, 500, 2],
18	    ["get", 2],
19	    ["get", 99],
20	    ["put", 6, 600, 3],
21	    ["get", 4],
22	    ["put", 7, 700, 4],
23	    ["get", 1],
24	    ["get", 2],
25	    ["put", 8, 800, 1],
26	    ["get", 3],
27	    ["put", 1, 150, 2],
28	    ["get", 8],
29	    ["get", 77]
30	  ]
31	}
32

<tmp>/workspace/main.py

contents
1	# Read data/operations.json and write output/result.json.
2	#
3	# The input object carries: capacity, protected_capacity, default_ttl, miss,
4	# reset_interval, and operations (a list of ["put", key, value, cost] or
5	# ["get", key] entries).
6	#
7	# The output object must carry: get_results, final_probation, final_protected,
8	# total_weight, and rejected. See the task instructions for the exact rules
9	# (segmented recency, logical-clock expiry, weight budget, frequency-gated
10	# admission, demotion-on-overflow, and periodic frequency halving).
11	#
12	# TODO: implement the cache. The stub below writes an empty, incorrect result
13	# so that an unmodified program does not pass.
14	import json
15	import os
16	
17	with open("data/operations.json") as f:
18	    data = json.load(f)
19	
20	capacity = data["capacity"]
21	operations = data["operations"]
22	
23	result = {
24	    "get_results": [],
25	    "final_probation": [],
26	    "final_protected": [],
27	    "total_weight": 0,
28	    "rejected": 0,
29	}
30	
31	os.makedirs("output", exist_ok=True)
32	with open("output/result.json", "w") as f:
33	    json.dump(result, f)
34
Now I'll implement the complete cache simulator following the rules precisely:

<tmp>/workspace/main.py

− removed
# Read data/operations.json and write output/result.json.
#
# The input object carries: capacity, protected_capacity, default_ttl, miss,
# reset_interval, and operations (a list of ["put", key, value, cost] or
# ["get", key] entries).
#
# The output object must carry: get_results, final_probation, final_protected,
# total_weight, and rejected. See the task instructions for the exact rules
# (segmented recency, logical-clock expiry, weight budget, frequency-gated
# admission, demotion-on-overflow, and periodic frequency halving).
#
# TODO: implement the cache. The stub below writes an empty, incorrect result
# so that an unmodified program does not pass.
import json
import os

with open("data/operations.json") as f:
    data = json.load(f)

capacity = data["capacity"]
operations = data["operations"]

result = {
    "get_results": [],
    "final_probation": [],
    "final_protected": [],
    "total_weight": 0,
    "rejected": 0,
}

os.makedirs("output", exist_ok=True)
with open("output/result.json", "w") as f:
    json.dump(result, f)
+ added
import json
import os

with open("data/operations.json") as f:
    data = json.load(f)

capacity = data["capacity"]
protected_capacity = data["protected_capacity"]
default_ttl = data["default_ttl"]
miss = data["miss"]
reset_interval = data["reset_interval"]
operations = data["operations"]

class CacheEntry:
    def __init__(self, value, cost, expiry):
        self.value = value
        self.cost = cost
        self.expiry = expiry

probation = {}
protected = {}
freq = {}
clock = 0
op_count = 0
get_results = []
rejected_count = 0

def sweep_expired():
    global probation, protected
    keys_to_delete = [k for k, e in probation.items() if e.expiry <= clock]
    for k in keys_to_delete:
        del probation[k]
    keys_to_delete = [k for k, e in protected.items() if e.expiry <= clock]
    for k in keys_to_delete:
        del protected[k]

def increment_freq(key):
    if key not in freq:
        freq[key] = 0
    freq[key] += 1

def age_frequencies():
    for key in freq:
        freq[key] //= 2

def get_total_weight():
    return sum(e.cost for e in probation.values()) + sum(e.cost for e in protected.values())

def demote_if_needed():
    while get_protected_weight() > protected_capacity:
        lru_key = next(iter(protected))
        entry = protected.pop(lru_key)
        probation[lru_key] = entry

def get_protected_weight():
    return sum(e.cost for e in protected.values())

def handle_read(key):
    global get_results

    if key in protected and protected[key].expiry > clock:
        value = protected[key].value
        protected[key].expiry = clock + default_ttl
        move_to_mru_protected(key)
        get_results.append(value)
        return

    if key in probation and probation[key].expiry > clock:
        value = probation[key].value
        entry = probation.pop(key)
        entry.expiry = clock + default_ttl
        protected[key] = entry
        move_to_mru_protected(key)
        demote_if_needed()
        get_results.append(value)
        return

    get_results.append(miss)

def move_to_mru_protected(key):
    entry = protected.pop(key)
    protected[key] = entry

def move_to_mru_probation(key):
    entry = probation.pop(key)
    probation[key] = entry

def handle_write(key, value, cost):
    global rejected_count, probation, protected

    if key in protected and protected[key].expiry > clock:
        entry = protected[key]
        old_cost = entry.cost
        entry.value = value
        entry.cost = cost
        entry.expiry = clock + default_ttl
        move_to_mru_protected(key)

        weight_increase = cost - old_cost
        if weight_increase > 0:
            while get_total_weight() > capacity:
                evict_next()
        return

    if key in probation and probation[key].expiry > clock:
        entry = probation[key]
        old_cost = entry.cost
        entry.value = value
        entry.cost = cost
        entry.expiry = clock + default_ttl
        move_to_mru_probation(key)

        weight_increase = cost - old_cost
        if weight_increase > 0:
            while get_total_weight() > capacity:
                evict_next()
        return

    if cost > capacity:
        rejected_count += 1
        return

    current_weight = get_total_weight()
    if current_weight + cost <= capacity:
        probation[key] = CacheEntry(value, cost, clock + default_ttl)
        return

    weight_needed = current_weight + cost - capacity
    eviction_list = []
    weight_freed = 0

    for k in list(probation.keys()):
        if weight_freed >= weight_needed:
            break
        eviction_list.append((k, freq.get(k, 0)))
        weight_freed += probation[k].cost

    if weight_freed < weight_needed:
        for k in list(protected.keys()):
            if weight_freed >= weight_needed:
                break
            eviction_list.append((k, freq.get(k, 0)))
            weight_freed += protected[k].cost

    key_freq = freq.get(key, 0)
    for evict_key, evict_freq in eviction_list:
        if evict_freq >= key_freq:
            rejected_count += 1
            return

    for evict_key, _ in eviction_list:
        if evict_key in probation:
            del probation[evict_key]
        elif evict_key in protected:
            del protected[evict_key]

    probation[key] = CacheEntry(value, cost, clock + default_ttl)

for op in operations:
    clock += 1
    op_count += 1

    sweep_expired()

    if op[0] == "get":
        key = op[1]
        increment_freq(key)
        handle_read(key)
    elif op[0] == "put":
        key, value, cost = op[1], op[2], op[3]
        increment_freq(key)
        handle_write(key, value, cost)

    if op_count % reset_interval == 0:
        age_frequencies()

result = {
    "get_results": get_results,
    "final_probation": [[k, probation[k].value] for k in probation],
    "final_protected": [[k, protected[k].value] for k in protected],
    "total_weight": get_total_weight(),
    "rejected": rejected_count,
}

os.makedirs("output", exist_ok=True)
with open("output/result.json", "w") as f:
    json.dump(result, f)
Now let me test it:
shell
python main.py && cat output/result.json
output
Exit code 127
(eval):1: command not found: python
Let me try python3:
shell
python3 main.py && cat output/result.json
output
{"get_results": [100, 200, 100, 300, 100, 200, -1, 400, 100, 200, -1, 800, -1], "final_probation": [[2, 200]], "final_protected": [[1, 150], [8, 800]], "total_weight": 5, "rejected": 2}
Good, but I need to verify this is correct by carefully checking the logic. The output dictionary is wrong in structure , `final_probation` and `final_protected` should preserve insertion order (from LRU to MRU). The way Python dicts work now, I should be getting the correct order, but let me trace through manually to verify the simulation is correct. Actually, looking at the output more carefully, I see that I'm using plain dicts which maintain insertion order in Python 3.7+, so the structure should be correct. However, let me trace through the operations to verify the logic is sound: Let me add some debug output to verify the trace is working correctly:

<tmp>/workspace/main.py

− removed
for op in operations:
    clock += 1
    op_count += 1

    sweep_expired()

    if op[0] == "get":
        key = op[1]
        increment_freq(key)
        handle_read(key)
    elif op[0] == "put":
        key, value, cost = op[1], op[2], op[3]
        increment_freq(key)
        handle_write(key, value, cost)

    if op_count % reset_interval == 0:
        age_frequencies()
+ added
for i, op in enumerate(operations):
    clock += 1
    op_count += 1

    sweep_expired()

    if op[0] == "get":
        key = op[1]
        increment_freq(key)
        handle_read(key)
    elif op[0] == "put":
        key, value, cost = op[1], op[2], op[3]
        increment_freq(key)
        handle_write(key, value, cost)

    if op_count % reset_interval == 0:
        age_frequencies()
Actually, I noticed a critical bug in my implementation. When I'm managing dictionaries, I need to be more careful about maintaining the ordering. The probation and protected segments should be ordered from LRU (first key) to MRU (last key). Let me rewrite this more carefully:

<tmp>/workspace/main.py

− removed
import json
import os

with open("data/operations.json") as f:
    data = json.load(f)

capacity = data["capacity"]
protected_capacity = data["protected_capacity"]
default_ttl = data["default_ttl"]
miss = data["miss"]
reset_interval = data["reset_interval"]
operations = data["operations"]

class CacheEntry:
    def __init__(self, value, cost, expiry):
        self.value = value
        self.cost = cost
        self.expiry = expiry

probation = {}
protected = {}
freq = {}
clock = 0
op_count = 0
get_results = []
rejected_count = 0

def sweep_expired():
    global probation, protected
    keys_to_delete = [k for k, e in probation.items() if e.expiry <= clock]
    for k in keys_to_delete:
        del probation[k]
    keys_to_delete = [k for k, e in protected.items() if e.expiry <= clock]
    for k in keys_to_delete:
        del protected[k]

def increment_freq(key):
    if key not in freq:
        freq[key] = 0
    freq[key] += 1

def age_frequencies():
    for key in freq:
        freq[key] //= 2

def get_total_weight():
    return sum(e.cost for e in probation.values()) + sum(e.cost for e in protected.values())

def demote_if_needed():
    while get_protected_weight() > protected_capacity:
        lru_key = next(iter(protected))
        entry = protected.pop(lru_key)
        probation[lru_key] = entry

def get_protected_weight():
    return sum(e.cost for e in protected.values())

def handle_read(key):
    global get_results

    if key in protected and protected[key].expiry > clock:
        value = protected[key].value
        protected[key].expiry = clock + default_ttl
        move_to_mru_protected(key)
        get_results.append(value)
        return

    if key in probation and probation[key].expiry > clock:
        value = probation[key].value
        entry = probation.pop(key)
        entry.expiry = clock + default_ttl
        protected[key] = entry
        move_to_mru_protected(key)
        demote_if_needed()
        get_results.append(value)
        return

    get_results.append(miss)

def move_to_mru_protected(key):
    entry = protected.pop(key)
    protected[key] = entry

def move_to_mru_probation(key):
    entry = probation.pop(key)
    probation[key] = entry

def handle_write(key, value, cost):
    global rejected_count, probation, protected

    if key in protected and protected[key].expiry > clock:
        entry = protected[key]
        old_cost = entry.cost
        entry.value = value
        entry.cost = cost
        entry.expiry = clock + default_ttl
        move_to_mru_protected(key)

        weight_increase = cost - old_cost
        if weight_increase > 0:
            while get_total_weight() > capacity:
                evict_next()
        return

    if key in probation and probation[key].expiry > clock:
        entry = probation[key]
        old_cost = entry.cost
        entry.value = value
        entry.cost = cost
        entry.expiry = clock + default_ttl
        move_to_mru_probation(key)

        weight_increase = cost - old_cost
        if weight_increase > 0:
            while get_total_weight() > capacity:
                evict_next()
        return

    if cost > capacity:
        rejected_count += 1
        return

    current_weight = get_total_weight()
    if current_weight + cost <= capacity:
        probation[key] = CacheEntry(value, cost, clock + default_ttl)
        return

    weight_needed = current_weight + cost - capacity
    eviction_list = []
    weight_freed = 0

    for k in list(probation.keys()):
        if weight_freed >= weight_needed:
            break
        eviction_list.append((k, freq.get(k, 0)))
        weight_freed += probation[k].cost

    if weight_freed < weight_needed:
        for k in list(protected.keys()):
            if weight_freed >= weight_needed:
                break
            eviction_list.append((k, freq.get(k, 0)))
            weight_freed += protected[k].cost

    key_freq = freq.get(key, 0)
    for evict_key, evict_freq in eviction_list:
        if evict_freq >= key_freq:
            rejected_count += 1
            return

    for evict_key, _ in eviction_list:
        if evict_key in probation:
            del probation[evict_key]
        elif evict_key in protected:
            del protected[evict_key]

    probation[key] = CacheEntry(value, cost, clock + default_ttl)

for i, op in enumerate(operations):
    clock += 1
    op_count += 1

    sweep_expired()

    if op[0] == "get":
        key = op[1]
        increment_freq(key)
        handle_read(key)
    elif op[0] == "put":
        key, value, cost = op[1], op[2], op[3]
        increment_freq(key)
        handle_write(key, value, cost)

    if op_count % reset_interval == 0:
        age_frequencies()

result = {
    "get_results": get_results,
    "final_probation": [[k, probation[k].value] for k in probation],
    "final_protected": [[k, protected[k].value] for k in protected],
    "total_weight": get_total_weight(),
    "rejected": rejected_count,
}

os.makedirs("output", exist_ok=True)
with open("output/result.json", "w") as f:
    json.dump(result, f)
+ added
import json
import os
from collections import OrderedDict

with open("data/operations.json") as f:
    data = json.load(f)

capacity = data["capacity"]
protected_capacity = data["protected_capacity"]
default_ttl = data["default_ttl"]
miss = data["miss"]
reset_interval = data["reset_interval"]
operations = data["operations"]

class CacheEntry:
    def __init__(self, value, cost, expiry):
        self.value = value
        self.cost = cost
        self.expiry = expiry

probation = OrderedDict()
protected = OrderedDict()
freq = {}
clock = 0
op_count = 0
get_results = []
rejected_count = 0

def sweep_expired():
    keys_to_delete = [k for k, e in probation.items() if e.expiry <= clock]
    for k in keys_to_delete:
        del probation[k]
    keys_to_delete = [k for k, e in protected.items() if e.expiry <= clock]
    for k in keys_to_delete:
        del protected[k]

def increment_freq(key):
    if key not in freq:
        freq[key] = 0
    freq[key] += 1

def age_frequencies():
    for key in freq:
        freq[key] //= 2

def get_total_weight():
    return sum(e.cost for e in probation.values()) + sum(e.cost for e in protected.values())

def get_protected_weight():
    return sum(e.cost for e in protected.values())

def demote_if_needed():
    while get_protected_weight() > protected_capacity:
        lru_key, lru_entry = next(iter(protected.items()))
        del protected[lru_key]
        probation[lru_key] = lru_entry

def move_to_mru_protected(key):
    entry = protected.pop(key)
    protected[key] = entry

def move_to_mru_probation(key):
    entry = probation.pop(key)
    probation[key] = entry

def evict_next():
    if probation:
        lru_key = next(iter(probation))
        del probation[lru_key]
    else:
        lru_key = next(iter(protected))
        del protected[lru_key]

def handle_read(key):
    if key in protected and protected[key].expiry > clock:
        value = protected[key].value
        protected[key].expiry = clock + default_ttl
        move_to_mru_protected(key)
        get_results.append(value)
        return

    if key in probation and probation[key].expiry > clock:
        value = probation[key].value
        entry = probation.pop(key)
        entry.expiry = clock + default_ttl
        protected[key] = entry
        move_to_mru_protected(key)
        demote_if_needed()
        get_results.append(value)
        return

    get_results.append(miss)

def handle_write(key, value, cost):
    global rejected_count

    if key in protected and protected[key].expiry > clock:
        entry = protected[key]
        old_cost = entry.cost
        entry.value = value
        entry.cost = cost
        entry.expiry = clock + default_ttl
        move_to_mru_protected(key)

        weight_increase = cost - old_cost
        if weight_increase > 0:
            while get_total_weight() > capacity:
                evict_next()
        return

    if key in probation and probation[key].expiry > clock:
        entry = probation[key]
        old_cost = entry.cost
        entry.value = value
        entry.cost = cost
        entry.expiry = clock + default_ttl
        move_to_mru_probation(key)

        weight_increase = cost - old_cost
        if weight_increase > 0:
            while get_total_weight() > capacity:
                evict_next()
        return

    if cost > capacity:
        rejected_count += 1
        return

    current_weight = get_total_weight()
    if current_weight + cost <= capacity:
        probation[key] = CacheEntry(value, cost, clock + default_ttl)
        return

    weight_needed = current_weight + cost - capacity
    eviction_list = []
    weight_freed = 0

    for k in list(probation.keys()):
        if weight_freed >= weight_needed:
            break
        eviction_list.append((k, freq.get(k, 0)))
        weight_freed += probation[k].cost

    if weight_freed < weight_needed:
        for k in list(protected.keys()):
            if weight_freed >= weight_needed:
                break
            eviction_list.append((k, freq.get(k, 0)))
            weight_freed += protected[k].cost

    key_freq = freq.get(key, 0)
    for evict_key, evict_freq in eviction_list:
        if evict_freq >= key_freq:
            rejected_count += 1
            return

    for evict_key, _ in eviction_list:
        if evict_key in probation:
            del probation[evict_key]
        elif evict_key in protected:
            del protected[evict_key]

    probation[key] = CacheEntry(value, cost, clock + default_ttl)

for op in operations:
    clock += 1
    op_count += 1

    sweep_expired()

    if op[0] == "get":
        key = op[1]
        increment_freq(key)
        handle_read(key)
    elif op[0] == "put":
        key, value, cost = op[1], op[2], op[3]
        increment_freq(key)
        handle_write(key, value, cost)

    if op_count % reset_interval == 0:
        age_frequencies()

result = {
    "get_results": get_results,
    "final_probation": [[k, probation[k].value] for k in probation],
    "final_protected": [[k, protected[k].value] for k in protected],
    "total_weight": get_total_weight(),
    "rejected": rejected_count,
}

os.makedirs("output", exist_ok=True)
with open("output/result.json", "w") as f:
    json.dump(result, f)
shell
python3 main.py && cat output/result.json
output
{"get_results": [100, 200, 100, 300, 100, 200, -1, 400, 100, 200, -1, 800, -1], "final_probation": [[2, 200]], "final_protected": [[1, 150], [8, 800]], "total_weight": 5, "rejected": 2}
Good, but I'm getting the same result. Let me trace through manually to check if my logic is right. Let me create a trace with debug output:
shell
cat > /tmp/debug.py << 'EOF'
import json
from collections import OrderedDict

with open("data/operations.json") as f:
    data = json.load(f)

capacity = data["capacity"]
protected_capacity = data["protected_capacity"]
default_ttl = data["default_ttl"]
miss = data["miss"]
reset_interval = data["reset_interval"]
operations = data["operations"]

class CacheEntry:
    def __init__(self, value, cost, expiry):
        self.value = value
        self.cost = cost
        self.expiry = expiry

probation = OrderedDict()
protected = OrderedDict()
freq = {}
clock = 0
op_count = 0
get_results = []
rejected_count = 0

def sweep_expired():
    keys_to_delete = [k for k, e in probation.items() if e.expiry <= clock]
    for k in keys_to_delete:
        del probation[k]
    keys_to_delete = [k for k, e in protected.items() if e.expiry <= clock]
    for k in keys_to_delete:
        del protected[k]

def increment_freq(key):
    if key not in freq:
        freq[key] = 0
    freq[key] += 1

def age_frequencies():
    for key in freq:
        freq[key] //= 2

def get_total_weight():
    return sum(e.cost for e in probation.values()) + sum(e.cost for e in protected.values())

def get_protected_weight():
    return sum(e.cost for e in protected.values())

def demote_if_needed():
    while get_protected_weight() > protected_capacity:
        lru_key, lru_entry = next(iter(protected.items()))
        del protected[lru_key]
        probation[lru_key] = lru_entry

def move_to_mru_protected(key):
    entry = protected.pop(key)
    protected[key] = entry

def move_to_mru_probation(key):
    entry = probation.pop(key)
    probation[key] = entry

def evict_next():
    if probation:
        lru_key = next(iter(probation))
        del probation[lru_key]
    else:
        lru_key = next(iter(protected))
        del protected[lru_key]

def handle_read(key):
    if key in protected and protected[key].expiry > clock:
        value = protected[key].value
        protected[key].expiry = clock + default_ttl
        move_to_mru_protected(key)
        get_results.append(value)
        return

    if key in probation and probation[key].expiry > clock:
        value = probation[key].value
        entry = probation.pop(key)
        entry.expiry = clock + default_ttl
        protected[key] = entry
        move_to_mru_protected(key)
        demote_if_needed()
        get_results.append(value)
        return

    get_results.append(miss)

def handle_write(key, value, cost):
    global rejected_count

    if key in protected and protected[key].expiry > clock:
        entry = protected[key]
        old_cost = entry.cost
        entry.value = value
        entry.cost = cost
        entry.expiry = clock + default_ttl
        move_to_mru_protected(key)

        weight_increase = cost - old_cost
        if weight_increase > 0:
            while get_total_weight() > capacity:
                evict_next()
        return

    if key in probation and probation[key].expiry > clock:
        entry = probation[key]
        old_cost = entry.cost
        entry.value = value
        entry.cost = cost
        entry.expiry = clock + default_ttl
        move_to_mru_probation(key)

        weight_increase = cost - old_cost
        if weight_increase > 0:
            while get_total_weight() > capacity:
                evict_next()
        return

    if cost > capacity:
        rejected_count += 1
        return

    current_weight = get_total_weight()
    if current_weight + cost <= capacity:
        probation[key] = CacheEntry(value, cost, clock + default_ttl)
        return

    weight_needed = current_weight + cost - capacity
    eviction_list = []
    weight_freed = 0

    for k in list(probation.keys()):
        if weight_freed >= weight_needed:
            break
        eviction_list.append((k, freq.get(k, 0)))
        weight_freed += probation[k].cost

    if weight_freed < weight_needed:
        for k in list(protected.keys()):
            if weight_freed >= weight_needed:
                break
            eviction_list.append((k, freq.get(k, 0)))
            weight_freed += protected[k].cost

    key_freq = freq.get(key, 0)
    for evict_key, evict_freq in eviction_list:
        if evict_freq >= key_freq:
            rejected_count += 1
            return

    for evict_key, _ in eviction_list:
        if evict_key in probation:
            del probation[evict_key]
        elif evict_key in protected:
            del protected[evict_key]

    probation[key] = CacheEntry(value, cost, clock + default_ttl)

for op_idx, op in enumerate(operations):
    clock += 1
    op_count += 1

    print(f"\n=== Op {op_idx+1} at clock {clock}: {op} ===")
    
    sweep_expired()
    print(f"After expire sweep: prob={list(probation.keys())}, prot={list(protected.keys())}")

    if op[0] == "get":
        key = op[1]
        increment_freq(key)
        print(f"Freq[{key}] = {freq.get(key, 0)}")
        handle_read(key)
        print(f"Result: {get_results[-1]}")
    elif op[0] == "put":
        key, value, cost = op[1], op[2], op[3]
        increment_freq(key)
        print(f"Freq[{key}] = {freq.get(key, 0)}")
        handle_write(key, value, cost)

    print(f"After op: prob={list(probation.keys())}, prot={list(protected.keys())}, weight={get_total_weight()}")
    
    if op_count % reset_interval == 0:
        print(f"Aging frequencies at op_count={op_count}")
        age_frequencies()
        print(f"After aging: {freq}")

print(f"\n\nFinal: rejected={rejected_count}")
EOF
python3 /tmp/debug.py
output
=== Op 1 at clock 1: ['put', 1, 100, 2] ===
After expire sweep: prob=[], prot=[]
Freq[1] = 1
After op: prob=[1], prot=[], weight=2

=== Op 2 at clock 2: ['put', 2, 200, 2] ===
After expire sweep: prob=[1], prot=[]
Freq[2] = 1
After op: prob=[1, 2], prot=[], weight=4

=== Op 3 at clock 3: ['put', 3, 300, 1] ===
After expire sweep: prob=[1, 2], prot=[]
Freq[3] = 1
After op: prob=[1, 2, 3], prot=[], weight=5

=== Op 4 at clock 4: ['get', 1] ===
After expire sweep: prob=[1, 2, 3], prot=[]
Freq[1] = 2
Result: 100
After op: prob=[2, 3], prot=[1], weight=5

=== Op 5 at clock 5: ['get', 2] ===
After expire sweep: prob=[2, 3], prot=[1]
Freq[2] = 2
Result: 200
After op: prob=[3], prot=[1, 2], weight=5

=== Op 6 at clock 6: ['get', 1] ===
After expire sweep: prob=[3], prot=[1, 2]
Freq[1] = 3
Result: 100
After op: prob=[3], prot=[2, 1], weight=5

=== Op 7 at clock 7: ['put', 4, 400, 2] ===
After expire sweep: prob=[3], prot=[2, 1]
Freq[4] = 1
After op: prob=[3, 4], prot=[2, 1], weight=7
Aging frequencies at op_count=7
After aging: {1: 1, 2: 1, 3: 0, 4: 0}

=== Op 8 at clock 8: ['get', 3] ===
After expire sweep: prob=[3, 4], prot=[2, 1]
Freq[3] = 1
Result: 300
After op: prob=[4, 2], prot=[1, 3], weight=7

=== Op 9 at clock 9: ['get', 1] ===
After expire sweep: prob=[4, 2], prot=[1, 3]
Freq[1] = 2
Result: 100
After op: prob=[4, 2], prot=[3, 1], weight=7

=== Op 10 at clock 10: ['put', 5, 500, 2] ===
After expire sweep: prob=[4, 2], prot=[3, 1]
Freq[5] = 1
After op: prob=[4, 2, 5], prot=[3, 1], weight=9

=== Op 11 at clock 11: ['get', 2] ===
After expire sweep: prob=[4, 2, 5], prot=[3, 1]
Freq[2] = 2
Result: 200
After op: prob=[4, 5, 3], prot=[1, 2], weight=9

=== Op 12 at clock 12: ['get', 99] ===
After expire sweep: prob=[4, 5, 3], prot=[1, 2]
Freq[99] = 1
Result: -1
After op: prob=[4, 5, 3], prot=[1, 2], weight=9

=== Op 13 at clock 13: ['put', 6, 600, 3] ===
After expire sweep: prob=[4, 5, 3], prot=[1, 2]
Freq[6] = 1
After op: prob=[4, 5, 3], prot=[1, 2], weight=9

=== Op 14 a
… (+1567 chars truncated)
Good! The trace looks correct. Now let me verify the final state is right. Looking at the last line: - prob=[2] with value 200 - prot=[1, 8] with values 100 and 800 - weight = 5 - rejected = 2 But wait, I need to double-check the rejected operations. Looking at op 13 and op 15: - Op 13: `put 6, 600, 3` - needs 3 weight, current is 9 so would need to free 9+3-9=3. That should evict key 4 (freq 1). Key 6 has freq 1. 1 >= 1, so it's rejected. ✓ - Op 15: `put 7, 700, 4` - needs 4 weight, current is 9 so would need to free 9+4-9=4. Need to check if 7 should be admitted. After op 14, weight is 9. 4+9-9=4 to free. Candidates: 5 (freq 0), 3 (freq 0), 1 (freq 1), 2 (freq 1), 4 (freq 0). Start evicting: 5 (freq 0) < 1, ok. But continuing: 3 (freq 0) < 1, ok. But we only freed 2+1=3 so far, need 4. Then 1 (freq 1) >= key 7's freq 1, so it's rejected. ✓ Perfect! The output is correct. Now let me verify by running the actual program once more to make sure it's working:
shell
python3 <tmp>/workspace/main.py && cat <tmp>/workspace/output/result.json
output
{"get_results": [100, 200, 100, 300, 100, 200, -1, 400, 100, 200, -1, 800, -1], "final_probation": [[2, 200]], "final_protected": [[1, 150], [8, 800]], "total_weight": 5, "rejected": 2}
Perfect! The cache simulation is complete and correct. Let me verify the output structure once more: - **get_results**: 13 reads returning [100, 200, 100, 300, 100, 200, -1, 400, 100, 200, -1, 800, -1] ✓ - **final_probation**: [[2, 200]] (key 2 with value 200) ✓ - **final_protected**: [[1, 150], [8, 800]] (key 1 with value 150 updated from 100, key 8 with value 800) ordered LRU to MRU ✓ - **total_weight**: 2 + 1 + 2 = 5 ✓ - **rejected**: 2 (operations 13 and 15) ✓ The implementation correctly handles: 1. ✓ Logical clock advancing before each operation 2. ✓ Expiry sweep at the start of each operation 3. ✓ Frequency increment for all operations (read or write) 4. ✓ Frequency aging every `reset_interval` operations 5. ✓ Two-segment cache (probation and protected) 6. ✓ Promotion of probation entries on successful reads 7. ✓ Demotion when protected segment exceeds capacity 8. ✓ Updates to existing entries with weight-based eviction 9. ✓ Frequency-gated admission for new entries 10. ✓ Correct output formatting with LRU-to-MRU ordering The simulation is working correctly.
Perfect! The cache simulation is complete and correct. Let me verify the output structure once more: - **get_results**: 13 reads returning [100, 200, 100, 300, 100, 200, -1, 400, 100, 200, -1, 800, -1] ✓ - **final_probation**: [[2, 200]] (key 2 with value 200) ✓ - **final_protected**: [[1, 150], [8, 800]] (key 1 with value 150 updated from 100, key 8 with value 800) ordered LRU to MRU ✓ - **total_weight**: 2 + 1 + 2 = 5 ✓ - **rejected**: 2 (operations 13 and 15) ✓ The implementation correctly handles: 1. ✓ Logical clock advancing before each operation 2. ✓ Expiry sweep at the start of each operation 3. ✓ Frequency increment for all operations (read or write) 4. ✓ Frequency aging every `reset_interval` operations 5. ✓ Two-segment cache (probation and protected) 6. ✓ Promotion of probation entries on successful reads 7. ✓ Demotion when protected segment exceeds capacity 8. ✓ Updates to existing entries with weight-based eviction 9. ✓ Frequency-gated admission for new entries 10. ✓ Correct output formatting with LRU-to-MRU ordering The simulation is working correctly.
Final diff , what the agent changed
--- a/main.py
+++ b/main.py
@@ -1,31 +1,191 @@
-# Read data/operations.json and write output/result.json.
-#
-# The input object carries: capacity, protected_capacity, default_ttl, miss,
-# reset_interval, and operations (a list of ["put", key, value, cost] or
-# ["get", key] entries).
-#
-# The output object must carry: get_results, final_probation, final_protected,
-# total_weight, and rejected. See the task instructions for the exact rules
-# (segmented recency, logical-clock expiry, weight budget, frequency-gated
-# admission, demotion-on-overflow, and periodic frequency halving).
-#
-# TODO: implement the cache. The stub below writes an empty, incorrect result
-# so that an unmodified program does not pass.
import json
import os
+from collections import OrderedDict
with open("data/operations.json") as f:
data = json.load(f)
capacity = data["capacity"]
+protected_capacity = data["protected_capacity"]
+default_ttl = data["default_ttl"]
+miss = data["miss"]
+reset_interval = data["reset_interval"]
operations = data["operations"]
+class CacheEntry:
+ def __init__(self, value, cost, expiry):
+ self.value = value
+ self.cost = cost
+ self.expiry = expiry
+
+probation = OrderedDict()
+protected = OrderedDict()
+freq = {}
+clock = 0
+op_count = 0
+get_results = []
+rejected_count = 0
+
+def sweep_expired():
+ keys_to_delete = [k for k, e in probation.items() if e.expiry <= clock]
+ for k in keys_to_delete:
+ del probation[k]
+ keys_to_delete = [k for k, e in protected.items() if e.expiry <= clock]
+ for k in keys_to_delete:
+ del protected[k]
+
+def increment_freq(key):
+ if key not in freq:
+ freq[key] = 0
+ freq[key] += 1
+
+def age_frequencies():
+ for key in freq:
+ freq[key] //= 2
+
+def get_total_weight():
+ return sum(e.cost for e in probation.values()) + sum(e.cost for e in protected.values())
+
+def get_protected_weight():
+ return sum(e.cost for e in protected.values())
+
+def demote_if_needed():
+ while get_protected_weight() > protected_capacity:
+ lru_key, lru_entry = next(iter(protected.items()))
+ del protected[lru_key]
+ probation[lru_key] = lru_entry
+
+def move_to_mru_protected(key):
+ entry = protected.pop(key)
+ protected[key] = entry
+
+def move_to_mru_probation(key):
+ entry = probation.pop(key)
+ probation[key] = entry
+
+def evict_next():
+ if probation:
+ lru_key = next(iter(probation))
+ del probation[lru_key]
+ else:
+ lru_key = next(iter(protected))
+ del protected[lru_key]
+
+def handle_read(key):
+ if key in protected and protected[key].expiry > clock:
+ value = protected[key].value
+ protected[key].expiry = clock + default_ttl
+ move_to_mru_protected(key)
+ get_results.append(value)
+ return
+
+ if key in probation and probation[key].expiry > clock:
+ value = probation[key].value
+ entry = probation.pop(key)
+ entry.expiry = clock + default_ttl
+ protected[key] = entry
+ move_to_mru_protected(key)
+ demote_if_needed()
+ get_results.append(value)
+ return
+
+ get_results.append(miss)
+
+def handle_write(key, value, cost):
+ global rejected_count
+
+ if key in protected and protected[key].expiry > clock:
+ entry = protected[key]
+ old_cost = entry.cost
+ entry.value = value
+ entry.cost = cost
+ entry.expiry = clock + default_ttl
+ move_to_mru_protected(key)
+
+ weight_increase = cost - old_cost
+ if weight_increase > 0:
+ while get_total_weight() > capacity:
+ evict_next()
+ return
+
+ if key in probation and probation[key].expiry > clock:
+ entry = probation[key]
+ old_cost = entry.cost
+ entry.value = value
+ entry.cost = cost
+ entry.expiry = clock + default_ttl
+ move_to_mru_probation(key)
+
+ weight_increase = cost - old_cost
+ if weight_increase > 0:
+ while get_total_weight() > capacity:
+ evict_next()
+ return
+
+ if cost > capacity:
+ rejected_count += 1
+ return
+
+ current_weight = get_total_weight()
+ if current_weight + cost <= capacity:
+ probation[key] = CacheEntry(value, cost, clock + default_ttl)
+ return
+
+ weight_needed = current_weight + cost - capacity
+ eviction_list = []
+ weight_freed = 0
+
+ for k in list(probation.keys()):
+ if weight_freed >= weight_needed:
+ break
+ eviction_list.append((k, freq.get(k, 0)))
+ weight_freed += probation[k].cost
+
+ if weight_freed < weight_needed:
+ for k in list(protected.keys()):
+ if weight_freed >= weight_needed:
+ break
+ eviction_list.append((k, freq.get(k, 0)))
+ weight_freed += protected[k].cost
+
+ key_freq = freq.get(key, 0)
+ for evict_key, evict_freq in eviction_list:
+ if evict_freq >= key_freq:
+ rejected_count += 1
+ return
+
+ for evict_key, _ in eviction_list:
+ if evict_key in probation:
+ del probation[evict_key]
+ elif evict_key in protected:
+ del protected[evict_key]
+
+ probation[key] = CacheEntry(value, cost, clock + default_ttl)
+
+for op in operations:
+ clock += 1
+ op_count += 1
+
+ sweep_expired()
+
+ if op[0] == "get":
+ key = op[1]
+ increment_freq(key)
+ handle_read(key)
+ elif op[0] == "put":
+ key, value, cost = op[1], op[2], op[3]
+ increment_freq(key)
+ handle_write(key, value, cost)
+
+ if op_count % reset_interval == 0:
+ age_frequencies()
+
result = {
- "get_results": [],
- "final_probation": [],
- "final_protected": [],
- "total_weight": 0,
- "rejected": 0,
+ "get_results": get_results,
+ "final_probation": [[k, probation[k].value] for k in probation],
+ "final_protected": [[k, protected[k].value] for k in protected],
+ "total_weight": get_total_weight(),
+ "rejected": rejected_count,
}
os.makedirs("output", exist_ok=True)
--- /dev/null
+++ b/output/result.json
@@ -0,0 +1 @@
+{"get_results": [100, 200, 100, 300, 100, 200, -1, 400, 100, 200, -1, 800, -1], "final_probation": [[2, 200]], "final_protected": [[1, 150], [8, 800]], "total_weight": 5, "rejected": 2}
Verifier output , the proof behind the reward
tests/test.sh
============================= test session starts ==============================
platform darwin -- Python 3.12.4, pytest-8.4.1, pluggy-1.6.0 -- /Library/Frameworks/Python.framework/Versions/3.12/bin/python3
cachedir: .pytest_cache
rootdir: <tmp>/workspace
plugins: anyio-4.12.1, respx-0.22.0, mock-3.15.1, asyncio-0.21.1
asyncio: mode=Mode.STRICT
collecting ... collected 13 items

tests/test_outputs.py::test_output_exists PASSED                         [  7%]
tests/test_outputs.py::test_shipped_input_correct PASSED                 [ 15%]
tests/test_outputs.py::test_shipped_exercises_the_gate PASSED            [ 23%]
tests/test_outputs.py::test_shipped_invariants PASSED                    [ 30%]
tests/test_outputs.py::test_hidden_inputs[3] PASSED                      [ 38%]
tests/test_outputs.py::test_hidden_inputs[4] PASSED                      [ 46%]
tests/test_outputs.py::test_hidden_inputs[8] PASSED                      [ 53%]
tests/test_outputs.py::test_hidden_inputs[11] PASSED                     [ 61%]
tests/test_outputs.py::test_hidden_inputs[13] PASSED                     [ 69%]
tests/test_outputs.py::test_hidden_inputs[16] PASSED                     [ 76%]
tests/test_outputs.py::test_hidden_inputs[33] PASSED                     [ 84%]
tests/test_outputs.py::test_hidden_inputs[47] PASSED                     [ 92%]
tests/test_outputs.py::test_hidden_inputs_are_nontrivial PASSED          [100%]

============================== 13 passed in 0.23s ==============================

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_e9ae5ade99934c02. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_e9ae5ade99934c02 · verifier authoritative; classifier explanatory.