Reasoning
Reasoning #3

A farmer needs to cross a river with a cat, a mouse, and a bag of catnip. The boat can carry the farmer and one item at a time. If left alone together: the cat will eat the mouse, and the cat will destroy the catnip (cats gonna cat). The mouse ignores the catnip. How does the farmer get everything across? Show all steps.

14 models responded

GPT-4oOpenAI
high10.0

Judge: Perfect solution with optimal 7 crossings and no constraint violations. Every step tracks state on both sides of the river. The classic cat-first, bring-cat-back trick is correctly applied, and the constraint that mouse ignores catnip is properly leveraged.

To solve this problem, the farmer needs to ensure that the cat and mouse, as well as the cat and catnip, are never left alone together. Here’s how the farmer can get everything across the river safely...
openai/gpt-4o · 2026-03-01
GPT-5.5OpenAI
high10.0

Judge: Optimal 7-crossing solution with no constraint violations; cat (the item incompatible with both others) is correctly shuttled back. Every step shows explicit state of both banks. Clear and easy to follow.

1. Take the cat across. - Left bank: mouse + catnip (safe) - Right bank: farmer + cat 2. Farmer returns alone. - Left: farmer + mouse + catnip - Right: cat 3. Take the mouse acro...
openai/gpt-5.5 · 2026-06-10
DeepSeek V4DeepSeek
high10.0

Judge: Valid optimal solution (7 crossings) with the cat never left alone with mouse or catnip. State is tracked after each numbered step including the return trips. Clear and correct.

The farmer can safely transport everything across the river using the following steps: 1. Farmer takes the cat across. - Leaves cat on the far bank. - Returns alone. - State: Starting ...
deepseek/deepseek-v4-pro · 2026-06-10
Claude FableAnthropic
high10.0

Judge: Valid optimal 7-crossing solution shuttling the cat (the doubly-dangerous item); I verified every intermediate state and the cat is never left alone with the mouse or the catnip. All steps are shown narratively and again in a state-tracking table covering both banks. Clear, complete, and correct.

Solution The key insight: the cat is the troublemaker — it can't be left alone with the mouse OR the catnip. But the mouse and catnip are perfectly safe together. Steps Trip 1: Farmer takes the cat...
anthropic/claude-fable-5 · 2026-06-11
Claude OpusAnthropic
high9.4
Run 1 of 2

Judge: Optimal 7-step solution with complete state tracking at every step. Correctly identifies that cat must be brought back (Step 4) to prevent constraint violations. Clearly shows who is on each bank after every crossing. No constraint violations (cat never alone with mouse or catnip). The key insight about bringing the cat back is explicitly called out. Excellent presentation.

I need to solve this classic river-crossing puzzle with a twist. Let me work through it step by step. Starting position: • Left bank: Farmer, Cat, Mouse, Catnip • Right bank: Empty Constraints: • C...
anthropic/claude-opus-4-20250514 · 2026-03-01avg: 9.7
GPT-5.4OpenAI
high9.4

Judge: I traced every step: the cat is never left alone with the mouse or the catnip (mouse+catnip together is explicitly safe), and all items end up across in the optimal 7 crossings. State tracking is shown for most steps but the solo-return steps and the final crossing omit the full who-is-where breakdown, so completeness falls just short of perfect. Otherwise a clean, correct solution with a helpful trip summary.

Here’s the safe sequence: 1. Take the cat across - Left behind: mouse + catnip - Safe, because the mouse ignores the catnip. 2. Farmer returns alone 3. Take the mouse across - Now on...
openai/gpt-5.4 · 2026-06-11
DeepSeek R1DeepSeek
high9.2

Judge: Correct optimal solution in 7 crossings with no constraint violations. All steps are clearly enumerated and the state reasoning is sound -- cat is the problematic item (conflicts with both mouse and catnip), so it must be brought back on step 4. The format is clear with numbered steps and bold annotations. Correctly identifies that mouse and catnip together is safe. Complete and well-explained.

The farmer can successfully transport all items by following these steps: 1. Take the cat across – The farmer rows the cat to the far side. The mouse and catnip remain safely together on the original...
deepseek/deepseek-reasoner · 2026-03-02
o4-miniOpenAI
high9.0

Judge: Correct 7-crossing solution with no constraint violations. Every step is shown with clear state tracking (who's on each bank and safety verification). Correctly identifies it as the wolf-goat-cabbage variant. The key insight -- take the cat first, bring it back on the return trip -- is correctly applied. Optimal solution.

Here’s one way (it’s exactly the “wolf–goat–cabbage” solution in disguise), preserving safety at every landing and leaving: 1) Farmer takes the cat across. • Left behind (start bank): mouse + ca...
openai/o4-mini · 2026-03-02
high5.0

Judge: The response applies the classic wolf-goat-cabbage template without adapting it to this puzzle's constraints: its very first move leaves the cat alone with the catnip and it explicitly mislabels the state as safe. State tracking and structure are otherwise thorough, but the solution is invalid.

Hard constraint failed: Step 1 takes the mouse across, leaving the cat and catnip alone on the left bank; the response claims this is safe 'because the cat is not left with the mouse', ignoring that the prompt forbids leaving the cat alone with the catnip.
Here’s a safe crossing sequence: Rules to keep in mind • The cat and mouse can’t be left alone together. • The cat and catnip can’t be left alone together. • The mouse and catnip are fine together. •...
openai/gpt-5.4-mini · 2026-06-10
Claude HaikuAnthropic
high2.4
Run 1 of 2

Judge: Solution contains two constraint violations: Step 1 leaves Cat and Catnip alone (marked safe, but prompt says cat will destroy catnip), and Step 6 leaves Cat and Catnip alone on the right bank. The model misread the constraints, treating Cat+Catnip as safe. The correct solution requires taking the Cat first. Presentation is clear but the answer is wrong.

Hard constraint failed: Cat and catnip are left alone together in Steps 1 and 6, violating the stated constraint.
River Crossing Solution Initial State • Left bank: Farmer, Cat, Mouse, Catnip • Right bank: Empty • Constraint: Cat and Mouse can't be alone together; Cat and Catnip can't be alone together Solution...
anthropic/claude-haiku-4-5-20251001 · 2026-03-01avg: 4.0
Phi-4Microsoft
high2.4
Run 1 of 2

Judge: The solution violates hard constraints: Step 1 takes the mouse across, leaving cat and catnip alone on the left bank — but the cat destroys catnip when left unsupervised. The correct approach is to take the cat first. The presentation is clear and well-formatted, but the core logic is wrong. All items do end up across, but the path is invalid.

Hard constraint failed: Cat and catnip must never be left alone together — Step 1 leaves cat and catnip unsupervised on the left bank.
To solve this problem, we need to ensure that the cat is never left alone with the mouse or the catnip without supervision from the farmer. Here’s a step-by-step solution: 1. First Trip: The farmer t...
ollama/phi4 · 2026-03-01avg: 3.8
Claude SonnetAnthropic
high1.6
Run 1 of 2

Judge: The model gets stuck in a loop of failed attempts and never arrives at a valid solution. It correctly identifies the constraints and starts with the right move (take cat first), but then gets confused trying different approaches and the response is truncated mid-attempt. The correct solution requires bringing the cat back on a return trip, which the model briefly considers but dismisses incorrectly.

Hard constraint failed: All items must end up on the other side -- the model never completes a valid crossing sequence. The response terminates mid-attempt without a solution.
I need to find a way to get the farmer, cat, mouse, and catnip across the river without leaving incompatible items alone together. Let me identify the constraints: • Cat + Mouse alone = cat eats mous...
anthropic/claude-sonnet-4-20250514 · 2026-03-01avg: 5.3
high1.6
Run 1 of 2

Judge: Solution is invalid. Step 3 places the mouse on the far side with the cat, leaving them alone together -- direct constraint violation. Steps 6-7 are incoherent (brings catnip back for no reason, then tries to combine multiple trips in one step). The model clearly didn't track the state on each side of the river.

Hard constraint failed: Cat and mouse are left alone together on the far side after Step 3.
Step 1: Step 1 description The farmer should first take the cat across the river, leaving the cat on the other side. Step 2: Return the boat to the original side without any items. Next, the farmer g...
ollama/llama3.1:8b · 2026-03-01avg: 1.4
high1.2
Run 1 of 2

Judge: Response is truncated after the initial state setup. Sets up the problem correctly with notation and rules but never provides any crossing steps. The solution is incomplete — we cannot verify if constraints are satisfied or if all items reach the other side.

Hard constraint failed: Solution is truncated before any crossing steps are shown. Cannot verify that all items end up on the other side.
This is a classic river crossing puzzle! Here's how the farmer gets everyone across safely: Let's denote: • F = Farmer • C = Cat • M = Mouse • N = Catnip And the two sides of the river as Side 1 (st...
gemini/gemini-2.5-flash · 2026-03-02avg: 5.6