SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

game-of-life-step

claude-code claude-haiku-4-5 ✓ resolved GOOD_SUCCESS 10 turns · 43 tok in · 2,023 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
EvidenceAll 6 tests passed including the hidden alternates test which runs 12 random board cases with varying dimensions (6-11 rows/cols), generation counts (1-4), and wall layouts. The agent's implementation correctly: (1) implements toroidal wrapping with modulo arithmetic, (2) preserves walls (value 2) unchanged, (3) only counts cells with value 1 as living neighbors, (4) applies Conway rules (survive 2-3, birth 3), and (5) applies all updates simultaneously. The test_hidden_alternates test verifies correctness on multiple random cases, and test_shipped_correct verifies against an independent reference evolution implementation, confirming the solution is algorithmically correct, not hardcoded."
Root causeThe agent correctly understood the toroidal Game of Life specification with wall handling, implemented an efficient and correct solution using modulo arithmetic for wrapping and proper neighbor-counting logic, and the solution passes all verification tests including 12 hidden random test cases."
RecommendationN/A - task is fine
Trajectory
Tool-by-tool agent trajectory
9 tool calls · 3 tool types · 18 steps
I'll start by reading the board file, config, and the stub to understand the current state.

<tmp>/workspace/main.py

contents
1	# Starter stub for the toroidal Game-of-Life task.
2	#
3	# It reads the starting board from data/grid.csv and the run settings from
4	# data/config.json, then (for now) just copies the board straight through
5	# to output/next.csv WITHOUT advancing any generations. Replace the body so
6	# it actually evolves the board the requested number of steps under the rules
7	# described in the task.
8	
9	import csv
10	import json
11	import os
12	
13	with open("data/grid.csv") as f:
14	    grid = [[int(x) for x in row] for row in csv.reader(f) if row]
15	
16	with open("data/config.json") as f:
17	    config = json.load(f)
18	
19	generations = int(config["generations"])  # number of steps to advance
20	topology = config["topology"]
21	
22	# TODO: replace this passthrough with the evolved board. As written it ignores
23	# the rules and the generation count, so it does not produce the requested board.
24	next_grid = grid
25	
26	os.makedirs("output", exist_ok=True)
27	with open("output/next.csv", "w", newline="") as f:
28	    csv.writer(f).writerows(next_grid)
29

<tmp>/workspace/data/grid.csv

contents
1	1,1,0,0,0,0,0,1
2	0,0,0,0,1,1,0,1
3	0,2,0,0,1,0,0,0
4	0,0,0,0,0,0,2,0
5	1,0,0,0,0,0,0,0
6	1,0,1,1,0,0,0,1
7

<tmp>/workspace/data/config.json

contents
1	{"topology": "toroidal", "generations": 3}
2
Now I'll implement the toroidal Game of Life logic. The key points: 1. Wrap-around topology (torus) 2. Walls (value 2) are fixed and never counted as neighbors 3. Only cells with value 1 count as alive neighbors 4. Apply standard Conway rules to non-wall cells

<tmp>/workspace/main.py

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

def count_live_neighbors(grid, r, c):
    """Count living neighbors (1s only) in a toroidal grid, ignoring walls."""
    rows = len(grid)
    cols = len(grid[0])
    count = 0
    for dr in [-1, 0, 1]:
        for dc in [-1, 0, 1]:
            if dr == 0 and dc == 0:
                continue
            nr = (r + dr) % rows
            nc = (c + dc) % cols
            if grid[nr][nc] == 1:
                count += 1
    return count

def evolve_generation(grid):
    """Apply one step of Conway's Game of Life with toroidal topology."""
    rows = len(grid)
    cols = len(grid[0])
    next_grid = [[0] * cols for _ in range(rows)]

    for r in range(rows):
        for c in range(cols):
            if grid[r][c] == 2:
                # Walls stay walls
                next_grid[r][c] = 2
            else:
                # Count live neighbors for non-wall cells
                live_neighbors = count_live_neighbors(grid, r, c)

                if grid[r][c] == 1:
                    # Living cell survives with 2 or 3 live neighbors
                    next_grid[r][c] = 1 if live_neighbors in [2, 3] else 0
                else:
                    # Empty cell becomes alive with exactly 3 live neighbors
                    next_grid[r][c] = 1 if live_neighbors == 3 else 0

    return next_grid

# Advance the board for the requested number of generations
for _ in range(generations):
    grid = evolve_generation(grid)

next_grid = grid
Now let me verify the implementation by running the script:
shell
python main.py
output
Exit code 127
(eval):1: command not found: python
Let me try python3:
shell
python3 main.py
output
(Bash completed with no output)
Good, it ran successfully. Let me check the output to verify it's correct:

<tmp>/workspace/output/next.csv

contents
1	0,1,1,1,0,1,0,0
2	0,1,1,0,0,0,0,0
3	0,2,0,0,0,0,0,0
4	1,1,0,0,0,0,2,0
5	1,1,0,0,0,0,0,0
6	1,0,1,0,0,0,0,0
7
Perfect! The script has successfully evolved the board through 3 generations. Let me verify the logic by manually tracing one cell to ensure correctness. Let me also check that the walls (value 2) remained unchanged:
shell
grep "2" output/next.csv | head -1
output
0,2,0,0,0,0,0,0
Good, the walls (2s) are preserved. Let me verify the dimensions match:
shell
echo "Input board:" && wc -l data/grid.csv && echo "Output board:" && wc -l output/next.csv && echo "Input cols:" && head -1 data/grid.csv | tr ',' '\n' | wc -l && echo "Output cols:" && head -1 output/next.csv | tr ',' '\n' | wc -l
output
Input board:
       6 data/grid.csv
Output board:
       6 output/next.csv
Input cols:
       8
Output cols:
       8
Excellent! The implementation is complete and working correctly: ✅ **Done.** The script now evolves the toroidal Game-of-Life board through the requested 3 generations. Key implementation details: - **Toroidal wrapping**: Cell neighbors wrap around edges using modulo arithmetic - **Walls preserved**: Cells with value 2 remain unchanged and never count as living neighbors - **Conway rules applied**: Living cells survive with 2-3 neighbors, empty cells birth with exactly 3 neighbors - **Simultaneous updates**: All cells are evaluated from the current generation before updating to the next The output board at `output/next.csv` has the same 6×8 dimensions as the input, with walls maintained at their original positions (row 3, col 2 and row 4, col 7).
Excellent! The implementation is complete and working correctly: ✅ **Done.** The script now evolves the toroidal Game-of-Life board through the requested 3 generations. Key implementation details: - **Toroidal wrapping**: Cell neighbors wrap around edges using modulo arithmetic - **Walls preserved**: Cells with value 2 remain unchanged and never count as living neighbors - **Conway rules applied**: Living cells survive with 2-3 neighbors, empty cells birth with exactly 3 neighbors - **Simultaneous updates**: All cells are evaluated from the current generation before updating to the next The output board at `output/next.csv` has the same 6×8 dimensions as the input, with walls maintained at their original positions (row 3, col 2 and row 4, col 7).
Final diff , what the agent changed
--- a/main.py
+++ b/main.py
@@ -19,8 +19,49 @@
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.
+def count_live_neighbors(grid, r, c):
+ """Count living neighbors (1s only) in a toroidal grid, ignoring walls."""
+ rows = len(grid)
+ cols = len(grid[0])
+ count = 0
+ for dr in [-1, 0, 1]:
+ for dc in [-1, 0, 1]:
+ if dr == 0 and dc == 0:
+ continue
+ nr = (r + dr) % rows
+ nc = (c + dc) % cols
+ if grid[nr][nc] == 1:
+ count += 1
+ return count
+
+def evolve_generation(grid):
+ """Apply one step of Conway's Game of Life with toroidal topology."""
+ rows = len(grid)
+ cols = len(grid[0])
+ next_grid = [[0] * cols for _ in range(rows)]
+
+ for r in range(rows):
+ for c in range(cols):
+ if grid[r][c] == 2:
+ # Walls stay walls
+ next_grid[r][c] = 2
+ else:
+ # Count live neighbors for non-wall cells
+ live_neighbors = count_live_neighbors(grid, r, c)
+
+ if grid[r][c] == 1:
+ # Living cell survives with 2 or 3 live neighbors
+ next_grid[r][c] = 1 if live_neighbors in [2, 3] else 0
+ else:
+ # Empty cell becomes alive with exactly 3 live neighbors
+ next_grid[r][c] = 1 if live_neighbors == 3 else 0
+
+ return next_grid
+
+# Advance the board for the requested number of generations
+for _ in range(generations):
+ grid = evolve_generation(grid)
+
next_grid = grid
os.makedirs("output", exist_ok=True)
--- /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 0.26s ===============================

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_73c61f9a3409418a. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_73c61f9a3409418a · verifier authoritative; classifier explanatory.