Ciro Santilli @cirosantilli 40

Ciro Santilli 40 2025-12-13

 View more

arcprize.org/play?task=00d62c1b

Hard input constraints:

inputs have two colors: green and black

Hard output constraints:

output has three colors: black, green and yellow
output has same size as input
green is copied from input to output
- output differs from input by making some black pixels yellow. Which pixels are becoming yellow?
  - output differs from input by making inner regions (non-diagonal) yellow with non-diagonal flood fill

 Read the full article

ARC-AGI-1 problem / 007bbfb by

Ciro Santilli 40 2025-12-13

 View more

arcprize.org/play?task=007bbfb7

Hard input constraints:

inputs are 3x3
inputs contain only 2 colors monocolored: black and another

Hard output constraints:

output is 3x input width and height. Suggests that the output is a 3x3 grid based on the input.
- stronger: if output is split as a 3x3 grid, then each 3x3 block is either black or a copy as input. Which is which?
  - stronger: each pixel of the input determines if block is black or copy (final solution)
output contains only two colors: black and another
- stronger: the same two colors as input

Input output comparison:

input appears pasted on output multiple times: suggests it is being copy pasted

Hard output constraints:

output is 3x input width and height: suggests that the output is a 3x3 grid based on the input
If that is the case, let's try to figure out what is placed on each output grid.
Notice: each grid element is either blank or the input.
OK so let's determine what in the input determines each output grid.
Because input in 3x3 maybe there's a direct mapping.

 Read the full article

arc-like by

Ciro Santilli 40 2025-12-13

 Read the full article

re-arc by

Ciro Santilli 40 2025-12-13

 View more

github.com/michaelhodel/re-arc

By the author of ARC-DSL.

README says:

This repository presents code to procedurally generate examples for the ARC training tasks. For each of the 400 tasks, an example generator is provided.

arxiv.org/html/2404.07353v1 says:

Each generator is a standalone Python function merely making use of the DSL and functions from the random module from the standard library. The median generator consists of 40 lines of code and uses 22 DSL primitive calls and 10 calls to the random module.

Cool!

Original:

Generated:

 Read the full article

ARC-AGI problem generator by

Ciro Santilli 40 2025-12-13

 Read the full article

Unofficial ARC-AGI problem set by

Ciro Santilli 40 2025-12-13

 View more

This section is about unofficial ARC-AGI-like problem sets.

These are interesting from both a:

practical point of view, as they provide more training data for potential solvers. If you believe that they are representative that is of course.
theoretical point of view, as they might help to highlight missing or excessive presumptions of the official datasets

github.com/neoneye/arc-dataset-collection contains a fantastic collection of such datasets, with visualization at: neoneye.github.io/arc/

 Read the full article

Project Euler problem 974 by

Ciro Santilli 40 Created 2025-12-13 Updated 2025-12-25

 View more

projecteuler.net/problem=974

Numerical solution:

13313751171933973557517973175

Earliest known public leak:

Programs:

github.com/cirosantilli/project-euler-solvers/blob/master/solvers/974.py

 Read the full article

Project Euler problem 973 by

Ciro Santilli 40 Created 2025-12-13 Updated 2025-12-25

 View more

projecteuler.net/problem=973

Numerical solution:

427278142

Earliest known public leak:

github.com/lucky-bai/projecteuler-solutions/issues/104

Programs:

github.com/cirosantilli/project-euler-solvers/blob/master/solvers/973.py

Notes:

matharena.ai/?comp=euler--euler from MathArena claims Gemini 3 solved it
x.com/roanoke_gal/status/1997322744594125081 claims GPT-5.1 Pro solved it.

 Read the full article

Project Euler problem 968 by

Ciro Santilli 40 Created 2025-12-13 Updated 2025-12-25

 View more

projecteuler.net/problem=963

Numerical solution:

885362394

Earliest known public leak: github.com/lucky-bai/projecteuler-solutions/issues/98

Programs:

github.com/cirosantilli/project-euler-solvers/blob/master/solvers/968.py

 Read the full article

Project Euler problem 963 by

Ciro Santilli 40 Created 2025-12-13 Updated 2025-12-25

 View more

projecteuler.net/problem=963

Numerical solution:

55129975871328418

Earliest known public leak: github.com/lucky-bai/projecteuler-solutions/issues/98

Programs:

github.com/cirosantilli/project-euler-solvers/blob/master/solvers/963.py

 Read the full article

Project Euler problem 962 by

Ciro Santilli 40 Created 2025-12-13 Updated 2025-12-25

 View more

projecteuler.net/problem=962

Numerical solution:

Earliest known public leak: github.com/lucky-bai/projecteuler-solutions/pull/95

Programs:

github.com/cirosantilli/project-euler-solvers/blob/master/solvers/962.py

 Read the full article

Project Euler problem 960 by

Ciro Santilli 40 Created 2025-12-13 Updated 2025-12-25

 View more

projecteuler.net/problem=961

Numerical solution:

243559751

Earliest known public leak: github.com/lucky-bai/projecteuler-solutions/issues/93

Programs:

github.com/cirosantilli/project-euler-solvers/blob/master/solvers/960.py

 Read the full article

Project Euler problem 957 by

Ciro Santilli 40 2025-12-13

 View more

projecteuler.net/problem=957

Numerical solution:

367554579311

Earliest known public leak: github.com/lucky-bai/projecteuler-solutions/commit/f7d538c7fa68d4a502da6705fd7ec3afc89e0cf9#diff-37cf8442cb9ce8d4c7401df424ea9362634a8a8733caa930c07346ea624be24fR961

Programs: TODO!

matharena.ai/euler/ mentions that MathArena guys managed to solve it with GPT-5 and an agent.

 Read the full article

Project Euler problem 956 by

Ciro Santilli 40 Created 2025-12-13 Updated 2025-12-25

 View more

projecteuler.net/problem=956

Numerical solution:

882086212

Earliest known public leak: github.com/lucky-bai/projecteuler-solutions/commit/a6ff5a562e32d17b044638b72f831d7bcba96ef2

Programs:

github.com/cirosantilli/project-euler-solvers/blob/master/solvers/956.py

 Read the full article

Project Euler problem 955 by

Ciro Santilli 40 Created 2025-12-13 Updated 2025-12-25

 View more

projecteuler.net/problem=955

Numerical solution:

6795261671274

Earliest known public leak: github.com/lucky-bai/projecteuler-solutions/pull/89

Programs:

github.com/cirosantilli/project-euler-solvers/blob/master/solvers/955.py

 Read the full article

Project Euler problem 954 by

Ciro Santilli 40 Created 2025-12-13 Updated 2025-12-25

 View more

projecteuler.net/problem=954

Numerical solution:

736463823

Earliest known public leak: github.com/lucky-bai/projecteuler-solutions/pull/88

Programs:

github.com/cirosantilli/project-euler-solvers/blob/master/solvers/954.py

 Read the full article

MathArena Apex by

Ciro Santilli 40 2025-12-13

 View more

matharena.ai/apex/

A subsets of problems that they curate from competitions.

 Read the full article

Elliot Glazer by

Ciro Santilli 40 2025-12-13

 View more

Creator of FrontierMath.

Socials:

x.com/ElliotGlazer

 Read the full article

Information theoretical musings inspired by ARC-AGI by

Ciro Santilli 40 2025-12-13

 View more

The extreme overfitting case of training is to have a map where each input leads to one output.

However it is cool that this overfit does not allow you to compute the final input for which there is no known output.

This therefore forces the creation of more general solution rules.

While in some cases solutions can work for any input, in many others they require specific assumptions about input, but the model could simply check that the assumptions apply to all inputs and use them for the final algorithm.

Bibliography:

lewish.io/posts/how-to-beat-arc-agi-2

 Read the full article

Official ARC-AGI problem set by

Ciro Santilli 40 2025-12-13

 Read the full article

 There are unlisted articles, also show them or only show them.