Questions tagged [binary-matrix]

Indicates that the challenge involves the manipulation of binary matrices, matrices whose elements are all one of two possible values, typically 1 and 0, or True and False.

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Largest Binary Area

Take the sequence of all natural numbers in binary, (1, 10, 11, ..) then write them vertically beside each-other like this (least significant bit on top; 0s have ...
mousetail's user avatar
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Decoding a non injective bit matrix encoding

The problem Someone has created an encoding format for square bit matrices, however they have found it isn't perfect! One encoding may not decode to exactly one matrix, or it may not even be possible ...
Energize1828's user avatar
11 votes
9 answers
634 views

Find Sub-matrix with matched cell 1

You are given a matrix of size m x n where each cell can contain either 1 or 0. You need to find the largest square submatrix that contains only 1's. The output should be the area of the largest ...
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16 votes
12 answers
1k views

Is this a shift matrix?

A Shift matrix is a binary matrix with one superdiagonal or subdiagonal formed by only ones, everything else is a zero. A superdiagonal/subdiagonal is a diagonal parallel to the main diagonal, which ...
math scat's user avatar
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13 votes
8 answers
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Toggle some bits and get an actual square

Inspired by the title of the Toggle some bits and get a square challenge. In that challenge you output how many bits should be toggled, in order for the base-10 representation of the binary to become ...
Kevin Cruijssen's user avatar
11 votes
14 answers
2k views

CGAC2022 Day 5: Preparing an advent calendar

Part of Code Golf Advent Calendar 2022 event. See the linked meta post for details. It's time to prepare an advent calendar, but I've only got a large sheet of rectangular paper, randomly colored red ...
Bubbler's user avatar
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15 votes
14 answers
1k views

1 to N column and row sums

Inspiration There is a problem on the most recent AMC 12B test, the one held on November 16, 2022, which goes like this: (AMC 12B 2022, Question 17) How many \$4\times4\$ arrays whose entries are \$0\...
Aiden Chow's user avatar
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21 votes
6 answers
2k views

For xor Young (15+)

A Young diagram is a rectangular binary mask whose every row and every column are sorted in descending order. It is easy to check that every rectangular binary mask can be formed by xor-ing together a ...
loopy walt's user avatar
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23 votes
6 answers
977 views

Tic, Tac, stub your Toe

Find the max number of Xs you can fit onto a rectangular tic-tac-toe board of length l and height h without ever having 3 consecutive Xs in a row diagonally, horizontally, or vertically. This is a ...
JohnBGoode's user avatar
17 votes
8 answers
2k views

Scribble Pad for Nerds

aka. implement an easier version of 05ab1e's canvas element. Description The canvas element is used to draw ASCII lines on the screen. The (easier version of the) canvas element takes a list of ...
math scat's user avatar
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19 votes
7 answers
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Matrix Meets ASCII Art

A binary matrix represents a shape in the plane. 1 means a unit square at that position. 0 means nothing. The background is 0. For example, the array ...
Number Basher's user avatar
14 votes
7 answers
1k views

Euler characteristic of a binary matrix

A binary matrix represents a shape in the plane. 1 means a unit square at that position. 0 means nothing. The background is <...
alephalpha's user avatar
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19 votes
7 answers
1k views

Expand a matrix goo-ily

Input An \$m\$ by \$n\$ binary matrix, with \$m\$ and \$n\$ both at least 2. Think of the ones as gobs of melted cheese, which stretch as we expand the matrix horizontally and vertically. More ...
Jonah's user avatar
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6 votes
2 answers
378 views

Reveal all clues of Black Box

Black Box is a board game, Your task is to reveal all clues. What is black box Black box is a board game with hidden atoms, Your task is given input, All atoms, reveal all clues. I/O Input The atoms ...
Fmbalbuena's user avatar
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22 votes
6 answers
796 views

Check if a matrix is Zarankiewicz-maximal

My final-year project at the National University of Singapore is on Zarankiewicz's problem: What is the maximum number of 1s in an \$m×n\$ binary matrix (\$m\$ rows and \$n\$ columns) with no \$a×b\$ ...
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18 votes
20 answers
1k views

Generate a regular graph

Inspired by this Mathematica.SE post Given two positive integers \$n, k\$ with \$n > k \ge 1\$, output a binary \$n\times n\$ matrix such that every row and column contains exactly \$k\$ 1s, and ...
caird coinheringaahin g's user avatar
12 votes
9 answers
1k views

AoCG2021 Day 13: Defrag in action!

Part of Advent of Code Golf 2021 event. See the linked meta post for details. The story continues from AoC2017 Day 14. To recap: The disk is a rectangular grid with \$r\$ rows and \$c\$ columns. Each ...
Bubbler's user avatar
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19 votes
13 answers
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Compute matrix blockiness

Consider a non-empty binary matrix M and a natural number n. For the purposes of this challenge, M is said to have blockiness n if it can be built using adjacent square blocks of size n, where each ...
Luis Mendo's user avatar
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9 votes
9 answers
936 views

Neural Processing Lattice Checker

Consider the following 9 "row patterns", using 0s to represent empty cells and 1s to represent a full cell. Each pattern is associated with an integer \$n\$, such that \$0 \le n \le 8\$ (...
l4m2's user avatar
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9 votes
3 answers
321 views

How many dominoes can you fit here?

Much harder than Can this pattern be made with dominoes? Challenge A grid of width \$w\$ and height \$h\$ is given, filled with 1s and 0s. You can place a domino somewhere on the grid only if both ...
Bubbler's user avatar
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8 votes
6 answers
525 views

Group binary shapes together

Consider the following binary matrix: $$\begin{matrix} 1 & 0 & 1 \\ 1 & 0 & 0 \\ 0 & 1 & 1 \end{matrix}$$ The (1-indexed) co-ordinates of the \$1\$s here are \$(1,1), (1,3), (2,...
caird coinheringaahin g's user avatar
12 votes
11 answers
1k views

Peter is Puzzled!

As some of you may remember, Peter, who was a picky eater is now puzzled Peter. This time Peter got some puzzles as a present from his Aunt. He has tried a lot, but has failed to solve the puzzles. ...
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18 votes
11 answers
2k views

Count my Pluses

Your task is, to count how many pluses I have. What Pluses? The no plus: 0 Points - The naïve Plus: 1 Point + The double ...
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10 votes
4 answers
302 views

Venn of \$n\$ statements

Given a positive integer \$n\$, output \$n\$ 2D bool images with the same width and height such that: Each image should be 4-connected, i.e. for each two pixels that are true, you can start from one ...
l4m2's user avatar
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34 votes
26 answers
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Is there a single straight line in the matrix?

Inspired by Wzl Determine if a given square binary matrix has exactly one row or column consisting of entirely 1s, and the rest of the matrix is ...
caird coinheringaahin g's user avatar
20 votes
16 answers
2k views

Is there a left-right connection?

Task Given a square array of 0s and 1s, determine whether or not there exists a path of 1s connecting the leftmost and rightmost columns. A path can take steps of one unit up, down, left or right, ...
aeh5040's user avatar
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13 votes
2 answers
335 views

Count all my sheep

Sandbox Given a boolean matrix representing my grass field, sheep length \$n\$ and wool thickness \$k\$, you will have to count my sheep. A sheep is a single independent unbroken line of sheep length \...
Razetime's user avatar
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17 votes
7 answers
2k views

But, Is It Art?

But Is It Art? is an esolang created by ais523, where one step is break the program into orthogonally connected "tiles": A BBBB A B B AA CC A CC Each ...
caird coinheringaahin g's user avatar
24 votes
19 answers
1k views

Just Enough Ones

Challenge Given a positive integer \$n\$, count the number of \$n\times n\$ binary matrices (i.e. whose entries are \$0\$ or \$1\$) with exactly two \$1\$'s in each rows and two \$1\$'s in each column....
Delfad0r's user avatar
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25 votes
14 answers
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Is this an L-shape?

Background An L-shape is defined as a polyomino which can be made by extending two rectangular legs in orthogonal directions from a full square (called a pivot). The size of the square should be at ...
Bubbler's user avatar
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16 votes
18 answers
3k views

Calculate COVID spread

Because the coronavirus is still at large, I thought it would be fitting to have a epidemic-themed challenge. Challenge You are given a 2D array of people, where 1 ...
applemonkey496's user avatar
18 votes
6 answers
434 views

Secret ">" Stacking Challenge: grading

Background Tetris Grand Master 3 has a hidden grading system based on the shape of the stack at the end of the game, which is called Secret ">" Stacking Challenge. It consists of entirely ...
Bubbler's user avatar
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24 votes
9 answers
902 views

Maintain diagonal symmetry when placing N items on a square grid

Write a program that takes in two non-negative integers S and N in that order. S represents the side length of a square grid of . characters. N represents the ...
Calvin's Hobbies's user avatar
25 votes
14 answers
3k views

ASCII texturing

Write a function or a full program that applies an ASCII texture to a 2d shape. Inputs: shape, texture, dimensions(optionally). Both Shape and Texture can be given by any convenient method (2d ...
AZTECCO's user avatar
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32 votes
6 answers
2k views

Slash the matrix

You are given a matrix of forward and back slashes, for instance: //\\ \//\ //\/ A slash cuts along the diagonal of its cell corner-to-corner, splitting it in ...
ngn's user avatar
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9 votes
3 answers
372 views

Identical grids

You’re given two \$r×c\$ grids. Each cell contains either 0 or 1. What are the minimum number of swaps (between horizontally and vertically adjacent cell elements, no wrapping i.e no swapping between ...
Kiara Dan's user avatar
  • 221
32 votes
18 answers
8k views

To find islands of 1 and 0 in matrix

Given a two dimensional matrix of 0 and 1s. Find the number of island for 1s and 0s where neighbours are only in the horizontal and vertical. ...
KB joy's user avatar
  • 329
40 votes
4 answers
2k views

Dungeon Crawler

Input A binary matrix \$M\$ representing the walls of a dungeon. The position \$(x,y)\$ of the player within the dungeon. The direction \$d\$ that the player is currently facing (0 = North, 1 = East, ...
Arnauld's user avatar
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13 votes
16 answers
2k views

Trim that distracting background off!

Isn't it annoying when you're taking a picture, but the background detracts from the actual substance of the image? I'd say it is. I need to know how much I should crop so that I get rid of this ...
Mr. Xcoder's user avatar
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8 votes
15 answers
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Scoring 6,5,4 (AKA Ship, Captain, and Crew)

Inspired and looted from this dice challenge by Arnauld Input You are given a 5x1 or 1x5 (your choice) dice matrix which consist of binary 3x3 sub-matrices. Goal Given a valid dice matrix, you are ...
Veskah's user avatar
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21 votes
8 answers
2k views

Belarus rushnyk

We've got quite a few national flag challenges already: AU CH FI FR GB GB IS KR NP US... Here's another, somewhat more advanced one: Return or print the decorative pattern from Belarus's national ...
ngn's user avatar
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22 votes
10 answers
2k views

How much is my dice matrix worth?

Input A non-empty binary matrix consisting of 3x3 sub-matrices put side by side. Task Your task is to identify valid dice patterns (as described below) among the 3x3 sub-matrices. Each valid ...
Arnauld's user avatar
  • 186k
36 votes
7 answers
3k views

Where is that snake going?

Write a function (using as few bytes as possible) that takes a bi-dimensional array of any number of columns and rows in which: 0 represents empty block, ...
Adelin's user avatar
  • 403
26 votes
8 answers
2k views

Mutually Attacking Queens

Let an 8x8 chessboard be represented by any two distinct values, with one value being an empty square and the other being a queen. In the following examples, I use 0s as the empty squares and 1s as ...
JMigst's user avatar
  • 879
10 votes
2 answers
422 views

The Lonely Islands

Input: A 2D array containing two distinct (optional) values. I'll use 0 and 1 when explaining the rules. The input format is of course flexible. Challenge: Zeros are water, and ones are islands. In ...
Stewie Griffin's user avatar
13 votes
7 answers
499 views

Cutpoints in a maze

A maze is given as a matrix of 0s (walls) and 1s (walkable space) in any convenient format. Each cell is considered connected to its 4 (or fewer) orthogonal neighbours. A connected component is a set ...
ngn's user avatar
  • 15.2k
19 votes
1 answer
715 views

Advent Challenge 1: Help Santa unlock his present vault!

Next >> Descriptive Keywords (for searching): Make Two Matrices Equivalent, Overlap, Array, Find Challenge Santa has had a history of elves stealing presents from his vault in the past, so this ...
hyper-neutrino's user avatar
  • 41.1k
23 votes
3 answers
2k views

Decode Faux Braille

...
ngn's user avatar
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13 votes
5 answers
1k views

Is it bipartite?

A bipartite graph is a graph whose vertices can be divided into two disjoint set, such that no edge connects two vertices in the same set. A graph is bipartite if and only if it is 2-colorable. ...
Colera Su's user avatar
  • 2,421
18 votes
5 answers
926 views

Change the rules of Life

Life-like cellular automaton are cellular automaton that are similar to Conway's Game of Life, in that they operate on a (theoretically) infinitely large square grid, where each cell has exactly 8 ...
caird coinheringaahin g's user avatar