Binary is the base 2 number system. Use this tag for challenges involving base 2.
27
votes
24answers
1k views
Decompose binary into alternating subsequences
This was inspired by Problem 13 - Non-Repeating Binary of HP CodeWars' recent competition.
Let's take a random decimal number, say
727429805944311
and look at its binary representation:
...
16
votes
11answers
718 views
Sum of Binary Substrings
This challenge is simple, given a decimal number, convert to binary, and calculate the sum of the sub-strings of the binary number, whose length is shorter than the original number. Here is an ...
18
votes
12answers
4k views
When will I have a binary car?
I noticed that my car's odometer was at 101101 when I got to work today. Which is a cool number because it's binary (and a palindrome, but that's not important). Now, I want to know when the next time ...
7
votes
1answer
230 views
Model a probability table using 15-bit fixed probabilities
A histogram is an array of integers that counts the number of times a symbol occurs. For example, for the string "aaabbbabbdebabbbebebdbaaabbabaaaaeebeaabaaba" a histogram is a: 18, b: 18, c: 0, d: 2, ...
8
votes
4answers
313 views
Shortest binary number in range
Given two arbitrarily precise decimal numbers 0 ≤ x < y ≤ 1, compute the shortest (in digits) binary number b such that x ≤ b < y.
Output the binary digits of b after the binary ...
12
votes
12answers
1k views
Preparing a multiple choice test
Introduction
Note: this is not some kind of method to encourage cheating. As Cᴏɴᴏʀ O'Bʀɪᴇɴ already said, studying is the best solution for passing a test :3.
Consider the following answers to the ...
24
votes
6answers
3k views
1+1 = 10, 1+2 = 3
Write a function or program than can do simple arithmetic (addition, subtraction, multiplication and division) in both base 10 and base 2.
The function will take a mathematical expression as input, ...
9
votes
3answers
182 views
I-Ching pair binary computer
Introduction
I Ching is an ancient divination text and the oldest of the Chinese classics. It uses a type of divination called cleromancy, which produces apparently random numbers.
The basic unit of ...
3
votes
5answers
130 views
Binary Run-Length Encoding [duplicate]
Overview
Run-length encoding — sequences in which the same data value occurs in many consecutive data elements are stored as a single data value and count
When using run-length encoding:
Input: ...
22
votes
21answers
1k views
Compute the Binary Sierpinski Triangle Sequence
The Binary Sierpinski Triangle sequence is the sequence of numbers whose binary representations give the rows of the Binary Sierpinski Triangle, which is given by starting with a 1 in an infinite row ...
15
votes
29answers
2k views
Write out the Thue-Morse sequence
There's quite a few challenges on this site that ask you to print out a sequence, and this is no exception.
(The following explanation of the sequence for this challenge assumes the symbols in the ...
25
votes
24answers
2k views
Parenthifiable Binary Numbers
If you express some positive integer in binary with no leading zeros and replace every 1 with a ( and every 0 with a ), then will all the parentheses match?
In most cases they won't. For example, 9 ...
18
votes
16answers
2k views
Simplify binary
Challenge
Given a binary number as input through any means, "simplify" the number using a full program or a function.
Input
[binary]
binary is a number in binary that is over 0.
Output
Take ...
22
votes
13answers
786 views
Counting +1 primes
Define that the natural number p is a +1 prime of the natural number n if p is a prime number and the standard binary representation (i.e., without leading zeroes) of p can be obtained by adding ...
19
votes
20answers
1k views
Reverse and Invert a String
Reverse and Invert a String
Challenge
In this challenge. You'll be writing a program which will output or return the input, reversed and inverted.
First, each character should be converted to its ...
6
votes
3answers
286 views
Symmetric boolean functions as Zhegalkin polynomials
Let 𝔹 = ℤ2 = {0, 1} be the set of booleans. A symmetric boolean function in n arguments is a function fS : 𝔹n ↦ 𝔹 that checks if the number of its true arguments is in S, i. e. a ...
32
votes
23answers
3k views
Biplex: an important useless operator
Input
A list of between 1 and 255 positive integers (inclusive), each in the range 1 to 232 - 1 (inclusive).
Your input format does not need to be identical to the test cases.
Input without leading ...
31
votes
29answers
2k views
Numbers with multiple runs of ones
Task
Find the set of numbers such that the binary representation contains two or more runs of 1 separated by at least one 0.
For example, the for the numbers that are 4 bits long:
0 0000 ...
19
votes
2answers
805 views
Koopa Shell Sequence
In various Super Mario games green and red Koopa Troopa shells can slide frictionlessly on flat surfaces and destroy brick blocks that are in their way. When a shell hits a brick block the block ...
8
votes
3answers
174 views
Counting cycles in a folding and squashing process
In chaos theory, the horseshoe map is an example of how chaos arises in a simple process of folding and squashing. It goes like this: take an imaginary piece of dough, fold it, and finally squash it ...
39
votes
14answers
2k views
Generate the Temple Skyline Sequence
Consider the following process:
Take some non-negative integer N.
e.g. N = 571
Express it in binary with no leading zeroes. (Zero itself is the only exception, becoming 0.)
e.g. 571 = 1000111011 ...
27
votes
23answers
2k views
16-bit binary grid
Given any unsigned 16 bit integer, convert its decimal form (i.e., base-10) number into a 4x4 ASCII grid of its bits, with the most-significant bit (MSB) at the top left, least-significant bit (LSB) ...
6
votes
2answers
207 views
Print a table of numbers in decimal and 2**i bases
Computers live by binary. All programmers know binary.
But the 2**x bases are often neglected as non-practical, while they have beautiful relations to binary.
To show you one example of such a ...
0
votes
2answers
102 views
Generate ordered binary combinations without repetitions [closed]
Challenge
Write the shortest program that receives two signed integers n and i and for each i between 1 and 2^n - 1 returns the next ordered permutation based on the binary representation of the ...
16
votes
3answers
331 views
Toggle, Print, Repeat
This challenge is loosely inspired by the unimplemented esolang Pada.
Consider an array of 8 bits, all initialised to zero. We'll introduce a very minimalistic instruction set to print arbitrary ...
16
votes
7answers
1k views
Binary Images of Triangle Counts
My challenges tend to be a little bit hard and unattractive. So here something easy and fun.
Alcuin's sequence
Alcuin's sequence A(n) is defined by counting triangles. A(n) is the number of ...
7
votes
3answers
322 views
Nameless to Brainf**k converter
This is inspired by the Brainf*** to tinyBF converter challenge.
Brainf**k (which will be henceforth referred to as BF) is a well-known estoric programming language, so I won't go over it too much ...
23
votes
19answers
2k views
Find the next 1-sparse binary number
A positive integer N is K-sparse if there are at least K 0s between any two consecutive 1s in its binary representation.
So, the number 1010101 is 1-sparse whereas 101101 is not.
Your task is to ...
13
votes
46answers
4k views
Count the number of ones in unsigned 16 bit integer
Write some statement(s) which will count the number of ones in an unsigned sixteen bit integer.
For example, if a variable s = 1337, then set ones to 6 because 1337 as a sixteen bit binary number is ...
10
votes
11answers
668 views
Binary encryption
This is based on xkcd #153.
Make a program or named function which takes 2 parameters, each of which is a string or a list or array of bytes or characters. The second parameter will only contain ...
11
votes
22answers
1k views
String to Binary
This is a code golf challenge. Just like the title says, write a program to covert a string of ascii characters into binary.
For example:
"Hello World!"
should turn into
1001000 1100101 1101100 ...
18
votes
4answers
2k views
Convert numbers to binary… but you're allowed to use twos as well
Based on the "binary, but with twos" notation mentioned in this numberphile video, write a function that takes a single number as input and outputs all variations of that number in a "binary" system ...
6
votes
7answers
715 views
Find the simplest value between two values
Goal
Your goal is to find the simplest value in an open interval. In other words, given two values a,b with a<b, output the simplest x with a<x<b. This is a code golf, so fewest bytes wins.
...
17
votes
30answers
3k views
Convert a string of binary characters to the ASCII equivalents
Take a string of binary characters separated by a space, and convert it to an ASCII string.
For example...
1001000 1100101 1101100 1101100 1101111 100000 1010111 1101111 1110010 1101100 1100100
...
4
votes
8answers
719 views
Give me the Gray Code list of bit width n
The Gray Code is a sequence of binary numbers of bitwidth n where successive numbers differ only in one bit (see example output).
Reference
Example input:
3
Example output:
000
001
011
010
110
...
0
votes
2answers
2k views
Make a regex that matches certain binary numbers [closed]
Your task is to create a regular expression that matches most binary numbers with an even number of 0s and an odd number of 1s (e.g. "101100011").
The full criteria for the regex are:
matches 90% ...
6
votes
2answers
583 views
math with bitwise operators
objective
write a program that can perform addition, subtraction, multiplication, and division, using only bit-wise operators, by bit-wise operators i mean the equivalent of JavaScript &, |, ^, ...
-1
votes
5answers
428 views
change two bits by using only bitwise operations [closed]
try to write shortest possible variant of logic which converts binary input by this table:
00 -> 00
01 -> 10
10 -> 01
11 -> 11
You can use only bitwise and bitshift operations. I ...
10
votes
3answers
2k views
Bitwise Operators in Brainfuck
Your task is to create one brainfuck program for each of the following binary operators. Each program should take one or two 8-bit numbers (A and B) from input and calculate the specified operation:
...
7
votes
4answers
681 views
Convert from binary to unary in 7x7 Manufactoria
In the game manufactoria, take in a binary number and output that number of red pieces.
The catch? The board-size is only 7x7:
Here's the manufactoria code for the problem:
...
4
votes
6answers
599 views
Generating Binary shapes
How could we generate shapes or images using binary?
I got to messing around trying to create something that looked matrix like and got to thinking, wouldn't a great CodeGolf be to see who can make ...
5
votes
3answers
806 views
Implementing Binary Arithmetic
Given two binary numbers (strings containing 0s and 1s), perform operations on them, with one problem: You must keep them in binary. That means no going binary(integer(n1)+integer(n2)) or anything ...
18
votes
17answers
2k views
Calculate hamming weight with low hamming weight
Create a program that computes the hamming weight of a string. Winner is the program with the lowest hamming weight.
Rules:
Hamming weight for an ASCII character is defined as the total number of ...
1
vote
7answers
4k views
compute number of 1 bits in a binary representation of a number
The goal is to write a program that returns number of 1 bits in a given number.
examples
5 -> 2
1254 -> 6
56465 -> 8
goal
the winner is the code which runs in minimum time ...
11
votes
3answers
892 views
Convert from binary to negabinary
Given a binary integer inclusively between 0 and 1111111111111111 (i.e. a 16-bit unsigned integer) as input, output the same integer in negabinary.
The input can be in whatever format is most ...
13
votes
33answers
2k views
Print the amount of ones in a binary number without using bitwise operators
Description
Given a number, print the amount of 1s it has in binary representation.
Input
A number >= 0 in base 10 that won't exceed the highest number your language is able to handle.
Output
...
2
votes
11answers
496 views
position of the only 1 in a number in binary format
Given N is a number from this list : 1, 2, 4, 8, 16, .... 2^i
as you know there is only a single "1" in binary representation of above numbers.
Question : write a code to find out the position of ...
12
votes
6answers
1k views
Manchester encode a data stream
Manchester coding is a telecom protocol used in radio communications that guarantees bit transitions at a regular interval so a receiver can recover the clock rate from the data itself. It doubles the ...
7
votes
2answers
589 views
Floating point addition, without floats!
Your task is to write a program, in any language, that adds two floating point numbers together WITHOUT using any fractional or floating point maths. Integer maths is allowed.
Format
The format for ...
6
votes
1answer
2k views
Nokia mystery puzzle [closed]
A friend sent me this puzzle. I'm pretty sure solving it will require some programming. Can anyone crack it? The original is here in case of encoding issues in the past below.
Did you know that...
...
