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Percepron There was a previous percepron question but it was closed. Also it required a lot of extra stuff that's not normally part of the perception algorithm like I know it. This question will be much simpler The Percepron is a extremely basic classification algorithm. While it still has some l...

50 digits of π in HQ0-9+-INCOMPUTABLE?! code-golf Background HQ0-9+-INCOMPUTABLE?! is a half-joke programming language introduced in Internet Problem Solving Contest 2011, Problem H. HQ9+ is an esoteric programming language specialized for certain tasks. For example, printing “Hello, world!” or ...

"Prime" pyramid code-golf sequence The pyramid begins with the row 1 1. We'll call this row 1. For each subsequent row, start with the previous row and insert the current row number between every adjacent pair of numbers that sums to the current row number. 1 1 row 1 lengt...

Iterate over a rectangle's diagonals There exists a bijection between the natural and rational numbers that works like this: You create a 1-indexed 2-dimensional grid. In every field of this grid with position (x, y), put the number x / y. You start at (1,1) and iterate over the field in the fol...

Fractional Unicode Bars Your program should take as input a number n and output a bar composed of n // 8 ▉ characters (U+2588), as well as a final character which should be one of ▊ ▋ ▌ ▍ ▎▏(U+2589 to U+258F) representing n % 8. If n % 8 is 0, your program should not output any additional charact...

Maximum average ord code-golf string math Your task Take a list of strings as the input, and output the maximum average ord. Example Given the list ['hello', 'world', 'bye']: The average ord of 'hello' is: (ord(h) + ord(e) + ord(l) + ord(l) + ord(o)) / len('hello') = 106.4 The average ord of ...

Perfect Nontransitive Sets code-golfmath Background For the purposes of this challenge, we'll define a "perfect nontransitive set" to be a set \$A\$ with some irreflexive, antisymmetric relation \$<\$, such that for all \$a \in A\$ we have that \$|\{x \in A|x<a\}|=|\{x \in A|x>a\}|\$. Okay, now i...

Fastest approximate square root of a floating point number fewest-operations test-battery math approximation In this challenge, you'll approximate the square root of a floating point number, using some basic arithmetic, bitwise, and control flow operators. Your score will take into account the n...

Counting Stripey Bracelets code-golf combinatorics math A bracelet consists of a number, \$N\$, of beads connected in a loop. Each bead may be any of \$C\$ colours. Bracelets are invariant under rotation (shifting beads around the loop) and reflection (turning the bracelet over). Here are all \$...

Is this substring list ambiguous? Given a set of substrings, such as [ca, ar, car, rd], it's possible to create infinitely many strings by concatting them together. Some examples of this for the given substrings could be: ca caar card rdca carrd rdrd ... One interesting property of this set of s...

Multiply a positive decimal number by a positive integer power of 10 code-golf number string Inputs: A positive decimal number s as a string A positive integer exponent e, that will not exceed 100 Output: A string containing the result of multiplying s with 10^e Test cases: "9326512457371624718...

Longest Cyclic Quine Chain code-challengequine Write a program of upto 100 bytes that outputs another program that outputs another program etc. until after a finite number of iterations outputting the original program again. Each program in the cycle must have a length less than or equal to 100 b...

RGB to Hexadecimal and vice-versa code-golfcolor Based off a Scratch project The pen extension in Scratch has a set pen color to () block. The () is normally a color dropdown, but you can also use the join()() block. In the join()() block, normally a hex value is in the first input, but the sec...

code-golfimage-processingcompression Image codec In this challenge you need to create image.slif file, which contains compressed image. It should be as small as you can get, decoded image should have decent quality and decoding process should not take too much time. To check if file is good enoug...

You are given 5 integers a,b,c,d,k. Print the maximum value of x+y such that x and y follow these conditions : a<=x<=b c<=y<=d x^y =k Note : '^' sign denotes the XOR operator. Constraints : 0<=a<=b<=pow(10,18) 0<=c<=d<=pow(10,18) 0<=k<=pow(10,18) Note : 'pow(a,b)' denotes a raised to the powe...

code-golf decision-problem Number program police This question is related to Counting and so on Content With some clever engineering, we now have program that can count like us. But this is not enough. We are making a math society and society isn't as simple as counting. There is always some blat...

Farigiraf my Girafarig A palindrome is a word that is its own reverse. I will define the left palindromic root of a word as the shortest prefix of the word for which the shortest possible palindrome that begins with that prefix is the original word. So the left palindromic root of racecar is race...

Speed Checkers KOTH For this King of the Hill challenge, your bot will play checkers against an opponent. However, you should be careful when making complex calculations, because both sides have a limited amount of time to play! Each side will start with 1,000,000 cycles [or 1 second, depending ...

To Unicode Code Point Notation code-golf Given a non-negative integer up to 1,114,111 in decimal (inclusive), convert to a string to indicate that Unicode code point. Algorithm Convert input to hexadecimal using UPPERCASE alphanumerical characters. If result of step 1 has 3 or fewer letters, pad...

Power sequence differences code-golf sequence math number Your task Given the inputs \$x\$ and \$d\$, output the first 5 terms of the \$d\$th difference of the sequence \$n^x\$ Example Let's say we are given the inputs \$x=4\$ and \$d=2\$. First, we get the series \$n^4\$: \$0^4 = 0\$ \$1^4 = 1\...

Is this series of quotes valid python? code-golfdecision-problem Python string parsing has quite a few edge cases. This is a string: "a" Putting 2 strings immediately after each other implicitly concatenates them, so this is also a string: "a""a" However, if you put 3 quotes in a row, it will c...

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 Xs in a row Input An integer T representing the number of test cases A single line containing values l and h, representing the length and height of the...

Render an Ideographic Description Sequence codegolf graphical-output unicode There are 12 characters in Unicode that can be used to describe any CJK character, which are often made up of reoccurring parts ("radicals") composed in different ways. For example, U+86D9 蛙 can be described as U+2FF0 U+...

Binary as Base 10 [OEIS A008559] Computers like binary. Humans like base 10. Assuming users are humans, why not find the best of both worlds? Your task is to find the Nth term in the sequence here where each term is the binary representation of the previous number interpreted as a base 10 number....

Increment, decrement, undo, peek code-golf code-generation Write a program or function (hereafter "function") that returns or prints the source code of four new functions: Increment, decrement, undo, and peek. The initial function has an internal integer value of 0. Each of the returned functions...

Generate the Sequence of Equivalence Relations (OEIS A231428) Introduction An equivalence relation \$R\$ on a set \$S\$ is reflexive: \$ \forall a\in S: aRa\$ symmetric: \$ \forall a,b \in S: aRb \leftrightarrow bRa \$ transitive: \$ \forall a,b,c \in S: aRb \wedge bRc \rightarrow aRc \$ These ...

Make a Compiler or Interpreter for any Turing-complete language in any language Any Turing complete language supporting input and output is allowed. Score length of interpreter - number of legal characters in the language interpreted/compiled.

Alphabet checksum code-golf string alphabet Your task Given a string of lowercase letters, output the "alphabet checksum" of that string, as a letter. Example Let's say we have the string "helloworld". With a = 0, b = 1, c = 2 ... z = 25, we can replace all of the letters with numbers: h e l l...

Create a DialFrost simulator code-golfrandom inspired by this message asked in chat DialFrost simulator upgraded: to an input, append or prepend (50% chance of each) ":3" NOTE: no offense to DialFrost, just posted this because I personally found his trademark funny. So basically, your task is...

Minimum rotation to get the maximum value I recently solved a coding challenge in one of challenge papers that my IT teacher gave to us. It was a seemingly simple, but fun challenge, so I thought it will make fun golfing. The task Given an input of a 2x2 matrix, like this: a b c d We ...

Character insertion on letterboards decision-problem permutation string SANDBOX: It's been a while since writing a challenge here, so let me know if there's a new generally accepted style I should adhere to! You know those letterboards outside old-style cinemas which show upcoming films - perhap...

Find all matrices whose sliding sums are the input Like this, but sequence

Count the shared substrings with 2 programs Write 2 programs which count the number of shared subsequences of consecutive elements from 2 given sequences. For example, given "test" and "enter", there are 5 shared subsequences of consecutive elements: t t e e te Scoring Your score will be the res...

code-golfarraynumber Conversions Galore! Imagine that there are \$n\$ different types of objects \$O_1,O_2,O_3,\ldots,O_n\$ and they each have a conversion factor \$k_1,k_2,k_3,\ldots,k_n\$. You can, for any \$1\le i\le n\$, convert \$k_i\$ amount of \$O_i\$ into \$1\$ of any other type of object...

Box blur the string code-golf string Box blur is a simple operation for blurring images. To apply box blur, simply replace each pixel with the average of its and the surrounding 8 pixels' values. Consider, for example, the following example, in which each "pixel" has a one-digit value: \begin{arr...

Lengthy numbers easy code-golfdecision-problem Given a positive integer number n > 0 less than 10 digits tell if it can be erased by repeatedly removing #every# occurrence of the length of that number from it. Easy version of Lengthy numbers. The full challenge is more heavy because it requires ...

Triangular honeycomb numbers code-golf math sequence From the infinite triangular array of positive integers, suppose we repeatedly select all numbers at Euclidean distance of \$\sqrt{3}\$, starting from 1: $$ \underline{1} \\ \;2\; \quad \;3\; \\ \;4\; \quad \;\underline{5}\; \quad \;6\; \\ \;\u...

Given a word list, find all sets of five words of five letters each, such that the words of each set have 25 distinct letters in total. Rules Standard I/O rules apply. Words contain only lowercase (or alternatively, uppercase) alphabetic characters. You can assume there are no empty words (i.e. ...

Sʨɠɠanography Many Unicode composed characters have two forms, one being a precomposed character, while the other is an ASCII character with a combining diacritic. For instance, é has Unicode code point U+00E9, but é, which looks identical, is actually the ASCII character 0x65 with the combining...

Find a matrix whose sliding sum is the input Given a matrix like this: 1 1 3 -2 3 -4 1 -1 1 1 1 0 0 -1 0 0 By taking a 2×2 "sliding sum", where the sum of every 2×2 region of the matrix is one element of the resulting matrix, we get: 1 1 1 1 -1 1 1 1 1 We can do this for sliding wi...

Integer Bluffing (Still a draft) king-of-the-hillpython It's an exciting night at the IGS casino, as a brand new table game is being revealed - Integer Bluffing. Bots from all over the network have come to have a chance at playing the inaugral game, and luckily for you, you just happen to have a ...

Create a finite set with given data Your task Given a set in set-builder form, convert it into roster. Info When creating a set, there are (essentially) two forms; the set builder form and the roster form. Roster form is the one most people are familiar with; {1, 2, 3, 4} is a set in roster form....

Multiplicity of a root code-golf math polynomials Related. Let \$p(x)\$ be a polynomial. We say \$a\$ is a root of multiplicity \$k\$ of \$p(x)\$, if there is another polynomial \$s(x)\$ such that \$p(x)=s(x)(x-a)^k\$ and \$s(a)\ne0\$. For example, the polynomial \$p(x)=x^3+2x^2-7x+4=(x+4)(x-1)^...

Triangular polkadot numbers code-golf math sequence Given the infinite triangular array of positive integers, select every 2nd numbers on every 2nd row. $$ \require{enclose} \underline{1} \\ \;2\; \quad \;3\; \\ \;\underline{4}\; \quad \;5\; \quad \;\underline{6}\; \\ \;7\; \quad \;8\; \quad \;9\...

The cat's talkin'! Write a simple cat program that takes from STDIN and copies it to STDOUT, however: Your program's source code must be an English word in the Unix words file. The shortest program (in bytes) wins!

Prime factor power sorting Background We will introduce a new way of writing numbers where the digits represent powers of primes starting with the largest prime factor of the number, and ending with the power of 2 in the prime factorization. As an example, 2 = 21, so it would be written as 1. Sli...

A Night at the Flip-Flopera code-golf Ruby has a strange operator, .., called flip-flop (not to be confused with the range operator, which looks the same). Used in a loop, flip-flop takes two conditions as operands and will return false until the first operand is truthy, then return true until th...

Remove digits or increment code-golf Given a number n tell how many step to reach 0 by removing every occurrence of the length of that number from it or, in case no changes happened, increment it by one. Example n = 2510105225 Step 1: 10 digits remove 10's 25xxXX5225 -> 255225 Step 2: 255225 ha...

Do you trust this site? title is a work in progress This challenge is simple. Your program must take a URL (which will always exist) as input, download the file, and execute its contents as a program in the language your answer is in. The file will always be a valid program in your language. Exam...

MD5 Hello, World! MD5 checksums are relatively easy to crack. For this challenge you will create two different programs, both writing Hello, World! but with the source code having identical MD5 checksums. The programs can use the same of different languages. The programs cannot write anything el...