# Tagged Questions

for challenges involving optimizing a certain thing.

2answers
1k views

### Compute the maximum number of runs possible for as large a string as possible

[This question is a follow up to Compute the runs of a string ] A period p of a string w is any positive integer p such that w[i]=w[i+p] whenever both sides of this equation are defined. Let per(...
0answers
154 views

### What's so great about 1729? [closed]

This is not a duplicate of this question. This is asking for the nth number that can be represented as the sum of two cubes in two different ways, while that is asking for the n-th number that can be ...
4answers
671 views

### Actually Integer Metagolf

Background Actually (the successor to Seriously) is a stack-based imperative golfing language I created in November of 2015. Like many other golfing languages, it has one-byte commands that perform ...
8answers
563 views

### Find a maximal rectangle of 1s

Background I want to buy an plot of land and build my house on it. My house should be rectangular, and as large as possible; however, the available plots have lots of rocky areas that I cannot build ...
4answers
399 views

### “Finish work” as early as possible

Background Imagine for a moment that you have a mind-numbingly boring job. Every morning, you are given a collection of tasks that you should work on that day. Each task has a certain duration, and ...
4answers
311 views

### Choose Scenes for a Movie

Introduction Finally the movie company is financing your film. They have given you a maximum budget and they also set the running time of your movie. Now you can start with the pre-production. You ...
4answers
461 views

### Plurality Voting with Cellular Automata

There's a really important problem in cellular automata called the Majority problem: The majority problem, or density classification task is the problem of finding one-dimensional cellular ...
98answers
12k views

### What is the smallest positive base 10 integer that can be printed by a program shorter (in characters) than itself?

I think the question as above is clear, but just in case: Write a full program (not just a function) which prints a positive base 10 integer, optionally followed by a single newline. Qualifying ...
2answers
328 views

### Playing Billiards

In this code golf, you will have to determine the direction of the shortest shot that hits exactly n cushions before falling into a pocket. The billiard table is a 6 pocket pool table with the ...
0answers
95 views

### Robot optimization

Your task is to program a robot so that it reaches the hole in the ground on each of the maps within reasonable time. If the robot reaches the hole, it falls down into it and thus victory is assured, ...
0answers
168 views

### Finding the smallest grid of squares [closed]

Inspiration from Puzzling.SE. Suppose we have an m × n grid such that each element is a base 10 digit. We can read the numbers from such a grid so that we fix a starting element, go to one of the ...
3answers
695 views

### An optimization challenge with strange coins

You have n coins which each weigh either -1 or 1. Each is labelled from 0 to n-1 so you can tell the coins apart. You have one (magic) weighing device as well. At the first turn you can put as many ...
1answer
432 views

### An optimization version of the Hadamard problem

First, some definitions. A Hadamard matrix is a square matrix whose entries are either +1 or −1 and whose rows are mutually orthogonal. The Hadamard conjecture proposes that a Hadamard matrix of ...
4answers
362 views

### Approximate Square Formation

Background I have a bunch of square-shaped boxes of equal size, and since I'm a neat person, I want to arrange them all into a square formation. However, their number is not necessarily a perfect ...
4answers
453 views

### Find the largest independent set in a high-dimensional lattice-like graph

For a given positive integer n, consider all binary strings of length 2n-1. For a given string S, let L be an array of length n which contains the count of the number of 1s in each substring of ...
2answers
287 views

### Creasing for Loot

Introduction After a long battle, you have managed to defeat a Sphinx in a contest of riddles. The Sphinx, impressed with your skill, wishes to give you a reward commensurate with your cleverness, ...
2answers
2k views

### Shortest universal maze exit string

A maze on an N by N grid of square cells is defined by specifying whether each edge is a wall or not a wall. All outer edges are walls. One cell is defined as the start, and one cell is defined as the ...
6answers
984 views

### A determinant optimization challenge

Consider 30 by 30 Toeplitz matrices all of whose entries are 0 or 1. This challenge is a simple optimization challenge to find the matrix with the largest determinant possible. Input None Output A ...
8answers
1k views

### Uniquely separated pixels

For an N by N image, find a set of pixels such that no separation distance is present more than once. That is, if two pixels are separated by a distance d, then they are the only two pixels that are ...
1answer
233 views

### Minimum of a Polynomial in Python

What is the shortest amount of code that can find the minimum of an inputted polynomial? I realize that you can import packages like Numpy and others, but using only user defined functions, what is ...
7answers
618 views

### Optimize the Scralphabet

Scralphabet A normal bag of Scrabble tiles contains the following letters (? is a blank tile, which can stand for any other letter): ...
4answers
240 views

### Write a program that takes as close to 1 second sharp to execute in your language [closed]

Write a program that takes as close to 1 second Wall-time sharp to execute in your language. Anything goes except to have the processor sleep / pause / wait, by either internal or relying on external ...
4answers
617 views

### Build a minimum-clue Sudoku unsolver

My attempt at stating this question, but with a more objective solving criterion. Your task is to build a program or function that takes a solved Sudoku grid S in the format of your choice and ...
2answers
637 views

### Build a top-front-side puzzle solver

A top-front-side puzzle is a puzzle where you are required to construct a 3-D shape of (usually cubic) blocks given three orthogonal views: a top view, a front view, and a side view. For example, ...
2answers
407 views

### Implement multiplication by a constant with addition and bit shifts

While looking at the ARM instruction set, you notice that the ADD instruction has the so-called "Flexible second operand", which can be abused for quick multiplication. For example, the following ...
0answers
509 views

### Tetris Tangrams

Introduction Tangrams are a classic puzzle involving arranging/fitting blocks into various shapes. From the Chinese 七巧板 - literally meaning "seven boards of skill". Let's take this idea and use the ...
7answers
469 views

### Fastest array-by-array nearest neighbour search

Intro - Nearest neighbour comparison between two arrays is something that can be done very efficiently when only 1 variable per array is involved, because it can be done by sorting and then performing ...
7answers
7k views

### Is this even a word?

Your should write a program or function that takes a 4-character string as input and outputs a value indicating if the string is an English word or not. You are allowed to make mistakes in 15% of the ...
2answers
888 views

### Go and make it starry

In this contest you have to write a program, that accepts a black and white pixel image, and tries to alter it, such that the white shape forms star domain, with as few changes as possible. Allowed ...
0answers
223 views

### 0h h1: Logical optimization [closed]

I've written a recursive backtracking solver for the game 0h h1. It's a simple game that takes place on a square grid, and each cell can be empty, red, or blue. You are given an initial configuration, ...
1answer
326 views

### Crafting Canonically Cöcher Crosswords

The Setup Most of us are familiar with crossword numbering, which follows three basic rules: in a character grid consisting of blacks and whites (see below), any maximal contiguous horizontal or ...
4answers
1k views

### 5 Seconds to Find Pie

Pi times e (or Pie if you like ambiguous notation) to 100 decimal places is: 8.5397342226735670654635508695465744950348885357651149618796011301792286111573308075725638697104739439... (OIES A019609) ...
1answer
616 views

### Frogger Champion

The Game Most of us know about Frogger, the 80's era arcade game where the objective is to hop a frog safely across a busy highway and a hazard-filled pond to arrive safely at home. A challenge was ...
3answers
974 views

### Restricted memory optimization

The edit (or Levenshtein) distance between two strings is the minimal number of single character insertions, deletions and substitutions needed to transform one string into the other. If the two ...
1answer
1k views

### Domino Circuits

Scoreboard Here are the raw scores (i.e. domino counts) for VisualMelon's submission. I'll turn these into the normalised scores described below, when more answers come in. The existing solution can ...
2answers
273 views

### Shortest test for primality for byte [duplicate]

Write a function which gets as input a number (0 <= n <= 255) stored in 32-bit variable and returns non-zero integer if n is prime number and 0 otherwise. Considern = 0 and n = 1 as non-primes. ...
2answers
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### Mastermind strategy

I could only find code-golf challenges for Mastermind, so here's a code-challenge version that I would have liked to take on myself. An optimal strategy for the normal Mastermind game, MM(4,6), was ...
4answers
932 views

### Travelling Salesman

You are given, as a list or vector or whatever, a bunch of 3-tuples or whatever, where the first two things are strings, and the third thing is a number. The strings are cities, and the number is the ...
3answers
2k views

### Check If Two or More Variables Are All Equal to Zero in JavaScript

What is the shortest way to check if two or more variables are equal to 0 in JavaScript? I'm curious to know if there's something shorter than if(!x&&!y&&!z){...}.
2answers
572 views

### Saying a number in the shortest way

A string of digits (positive integer) can be converted to plain English in various ways. For instance, 115 can be read as "hundredfifteen", "oneonefive", "elevenfive", "twoonesfive". So question's ...
4answers
476 views

### Build a drug testing scheduler

In this problem on Puzzling.SE, I ask a question about determining the amounts of drug to use in a clinical test to minimize total drug usage and fulfill the requirements of the testing procedure. ...
0answers
112 views

### Using dictionaries, thesauruses, and similar databases, construct as large of a “See also” loop as possible [closed]

As I'm sure many of you know, synonyms can range from very similar to not-so-similar-but-I-can-see-how-it's-similar. It's common for dictionaries to use "See also" to denote occurrences of words that ...
1answer
1k views

### Minimal keystrokes needed to type a given text

We all know that programmers tend to be lazy. In order to maximize your free time, you decide to write a program that outputs a minimal number of keystrokes for text fed into it. Input: Text that ...
2answers
734 views

### Build a program that creates a minimal one-ohm resistor diagram for a given resistance

You are a contractor for a company who designs electrical circuits for the various products they make. One day, the company accidentally gets a huge shipment of one-ohm resistors and absolutely ...
2answers
858 views

### Implement superoptimizer for addition

The task is to write code that can find small logical formulae for sums of bits. The overall challenge is for your code to find the smallest possible propositional logical formula to check if the sum ...
3answers
723 views

### Who brings the croissants?

This question is inspired by a similar question first asked on StackOverflow by Florian Margaine, then asked in variant forms on CS by Gilles and on Programmers by GlenH7. This time, it's a code golf,...
1answer
141 views

### meeting point minimizing travel distance for participants? [closed]

The problem is to find the point minimizing the travel distance for around 100 persons in different regions who want to meet in the same place. Travel is by car not by plane. Assuming that I get ...
0answers
709 views

### Shortest 2-Player Game of Halma

In Chess, it's possible for the game to end after 4 moves (2 each) with a Fool's Mate. Your goal is to find the Fool's Mate of Halma: the 2-player game of Halma that minimises the number of turns ...
2answers
1k views

### Compact a Befunge program

Befunge is a 2-dimensional esoteric programming language. The basic idea is that (one-character) commands are placed on a 2-dimensional grid. Control flow walks across the grid, executing commands it ...
1answer
227 views

### Bob's Financial Planning (Maximize)

Bob's Financial Planning Bob lives in Pecunia. It is a small island city completely governed by the Pecunia City Council (PCC). PCC has decided to encourage foreign investments in the city by waiving ...