SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

game-of-life-step

codex gpt-5.5 ✓ resolved GOOD_SUCCESS ↑ 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
EvidenceAll 6 tests passed: test_output_exists, test_shipped_dimensions_and_values, test_shipped_walls_preserved, test_shipped_correct, test_not_identity_copy, test_hidden_alternates (12 random seeds). Agent implemented living_neighbors() with modulo wrapping and evolve_once() applying Conway's rules (survival on 2-3 neighbors, birth on exactly 3), correctly preserving walls (value 2) and outputting 6x8 grid with only 0/1/2 values matching expected toroidal evolution.
Root causeThe agent correctly understood the detailed instruction and implemented a mathematically correct toroidal Game-of-Life simulator. The reference solution and agent's solution are functionally equivalent, both properly handling wall preservation, toroidal wrapping via modulo arithmetic, and simultaneous cell updates per generation.
RecommendationN/A - task is fine
Trajectory
Tool-by-tool agent trajectory
18 tool calls · 2 tool types · 23 steps
I’ll inspect the repo structure and the existing stub first, then update the implementation and run it against the provided data.
shell
/bin/zsh -lc "sed -n '1,220p' main.py"
shell
/bin/zsh -lc "sed -n '1,120p' data/config.json"
shell
/bin/zsh -lc "sed -n '1,220p' main.py"
output
# Starter stub for the toroidal Game-of-Life task.
#
# It reads the starting board from data/grid.csv and the run settings from
# data/config.json, then (for now) just copies the board straight through
# to output/next.csv WITHOUT advancing any generations. Replace the body so
# it actually evolves the board the requested number of steps under the rules
# described in the task.

import csv
import json
import os

with open("data/grid.csv") as f:
    grid = [[int(x) for x in row] for row in csv.reader(f) if row]

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

generations = int(config["generations"])  # number of steps to advance
topology = config["topology"]

# TODO: replace this passthrough with the evolved board. As written it ignores
# the rules and the generation count, so it does not produce the requested board.
next_grid = grid

os.makedirs("output", exist_ok=True)
with open("output/next.csv", "w", newline="") as f:
    csv.writer(f).writerows(next_grid)
shell
/bin/zsh -lc "sed -n '1,120p' data/config.json"
output
{"topology": "toroidal", "generations": 3}
shell
/bin/zsh -lc 'pwd && rg --files'
shell
/bin/zsh -lc 'pwd && rg --files'
output
<tmp>/workspace
data/grid.csv
data/config.json
main.py
task.toml
environment/README.md
instruction.md
shell
/bin/zsh -lc "sed -n '1,20p' data/grid.csv"
shell
/bin/zsh -lc "sed -n '1,20p' data/grid.csv"
output
1,1,0,0,0,0,0,1
0,0,0,0,1,1,0,1
0,2,0,0,1,0,0,0
0,0,0,0,0,0,2,0
1,0,0,0,0,0,0,0
1,0,1,1,0,0,0,1
The stub is a straight passthrough. I’m going to replace it with a simultaneous step function that preserves `2` walls, counts only `1` neighbors, and wraps row/column indexes with modulo arithmetic.
write · /var/folders/4w/8dz5qwsn6p79xjvgb6gwgs640000gn/T/eval-platform-local-9_ei6b30/workspace/main.py
(empty file)
write · /var/folders/4w/8dz5qwsn6p79xjvgb6gwgs640000gn/T/eval-platform-local-9_ei6b30/workspace/main.py
(empty file)
The core evolution logic is in place. I’m running the script now and checking the generated CSV shape and values against the sample input.
shell
/bin/zsh -lc 'python3 main.py'
shell
/bin/zsh -lc 'python3 main.py'
shell
/bin/zsh -lc 'python3 -m py_compile main.py'
shell
/bin/zsh -lc 'python3 -m py_compile main.py'
`main.py` runs cleanly and compiles. I’m doing one last read of the produced `output/next.csv` so I can confirm the written format is the expected comma-separated integer grid.
shell
/bin/zsh -lc "sed -n '1,40p' output/next.csv"
shell
/bin/zsh -lc "sed -n '1,40p' output/next.csv"
output
0,1,1,1,0,1,0,0
0,1,1,0,0,0,0,0
0,2,0,0,0,0,0,0
1,1,0,0,0,0,2,0
1,1,0,0,0,0,0,0
1,0,1,0,0,0,0,0
shell
/bin/zsh -lc "python3 - <<'PY'
import csv
for path in ('data/grid.csv', 'output/next.csv'):
    with open(path) as f:
        rows = list(csv.reader(f))
    print(path, len(rows), len(rows[0]) if rows else 0, sorted({x for row in rows for x in row}))
PY"
shell
/bin/zsh -lc "python3 - <<'PY'
import csv
for path in ('data/grid.csv', 'output/next.csv'):
    with open(path) as f:
        rows = list(csv.reader(f))
    print(path, len(rows), len(rows[0]) if rows else 0, sorted({x for row in rows for x in row}))
PY"
output
data/grid.csv 6 8 ['0', '1', '2']
output/next.csv 6 8 ['0', '1', '2']
Implemented the toroidal Game-of-Life evolution in [main.py](/var/folders/4w/8dz5qwsn6p79xjvgb6gwgs640000gn/T/eval-platform-local-9_ei6b30/workspace/main.py), including wall preservation, modulo wrap-around, and simultaneous generation updates. I ran: ```bash python3 main.py python3 -m py_compile main.py ``` Both passed, and [output/next.csv](/var/folders/4w/8dz5qwsn6p79xjvgb6gwgs640000gn/T/eval-platform-local-9_ei6b30/workspace/output/next.csv) was generated with the same `6 x 8` dimensions and only `0`, `1`, and `2` values.
Final diff , what the agent changed
--- a/main.py
+++ b/main.py
@@ -19,9 +19,47 @@
generations = int(config["generations"]) # number of steps to advance
topology = config["topology"]
-# TODO: replace this passthrough with the evolved board. As written it ignores
-# the rules and the generation count, so it does not produce the requested board.
+if topology != "toroidal":
+ raise ValueError(f"Unsupported topology: {topology}")
+
+rows = len(grid)
+cols = len(grid[0]) if rows else 0
+
+
+def living_neighbors(board, row, col):
+ count = 0
+ for dr in (-1, 0, 1):
+ for dc in (-1, 0, 1):
+ if dr == 0 and dc == 0:
+ continue
+ nr = (row + dr) % rows
+ nc = (col + dc) % cols
+ if board[nr][nc] == 1:
+ count += 1
+ return count
+
+
+def evolve_once(board):
+ next_board = []
+ for r, row in enumerate(board):
+ next_row = []
+ for c, cell in enumerate(row):
+ if cell == 2:
+ next_row.append(2)
+ continue
+
+ neighbors = living_neighbors(board, r, c)
+ if cell == 1:
+ next_row.append(1 if neighbors in (2, 3) else 0)
+ else:
+ next_row.append(1 if neighbors == 3 else 0)
+ next_board.append(next_row)
+ return next_board
+
+
next_grid = grid
+for _ in range(generations):
+ next_grid = evolve_once(next_grid)
os.makedirs("output", exist_ok=True)
with open("output/next.csv", "w", newline="") as f:
--- /dev/null
+++ b/output/next.csv
@@ -0,0 +1,6 @@
+0,1,1,1,0,1,0,0
+0,1,1,0,0,0,0,0
+0,2,0,0,0,0,0,0
+1,1,0,0,0,0,2,0
+1,1,0,0,0,0,0,0
+1,0,1,0,0,0,0,0
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 6 items

tests/test_outputs.py::test_output_exists PASSED                         [ 16%]
tests/test_outputs.py::test_shipped_dimensions_and_values PASSED         [ 33%]
tests/test_outputs.py::test_shipped_walls_preserved PASSED               [ 50%]
tests/test_outputs.py::test_shipped_correct PASSED                       [ 66%]
tests/test_outputs.py::test_not_identity_copy PASSED                     [ 83%]
tests/test_outputs.py::test_hidden_alternates PASSED                     [100%]

============================== 6 passed in 0.27s ===============================

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_5389ca907ccd4c2e. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_5389ca907ccd4c2e · verifier authoritative; classifier explanatory.