Questions tagged [algorithm]
For challenges related to creating or implementing an algorithm.
31
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10
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Elect the Doge of Venice
The Venetian election system was... complicated.
The Great Council came together and put in an urn the ballots of all the councilors who were older than 30. The youngest councilor went to St Mark's ...
- 1,171
27
votes
52
answers
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Shortest Code to Find the Smallest Missing Positive Integer
Description
Given an unsorted array of integers, find the smallest positive integer that does not appear in the array. Your task is to write the shortest code possible to solve this problem.
Input
A ...
- 1,732
12
votes
10
answers
895
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Maximum of outer product of integer vectors (in linear time)
Introduction
Our goal is to efficiently find the maximum of a large amount of (redundant) data.
We define the outer product of vectors \$A\$ and \$B\$ as a matrix containing the products of all ...
- 221
7
votes
2
answers
476
views
NxM List Combination Closest to Target
Given a list of N lists, each containing M positive integers, and a separate list of M positive integers (target values), return a list of N scalars (integers with a value of 0 or more) that ...
- 757
21
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25
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Climbing the Bookshelf
Introduction
You're making a robot that can navigate a set of books of varying heights. It can climb books and jump off books, but if the distance is too big it will stop to prevent damage. To figure ...
- 5,420
1
vote
0
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Make me equal to 24 [duplicate]
Based on this game.
Description :
Based on Wikipedia's description.
The 24 Game is an arithmetical card game in which the objective is to find a way to manipulate four integers so that the end result ...
- 339
14
votes
9
answers
429
views
Taking the long route
Challenge
Your goal is to find the furthest point on a graph (from a provided start node). Your code doesn't need to handle cycles in the graph properly, but it might pose a fun challenge. For this ...
- 341
1
vote
1
answer
419
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Hacker Challenge: Guess the Correct Password
In an attempt to “liberate” their fellow birds, a group of highly intelligent hens are
attempting to compromise the zoo’s security system. To get access to the zoo’s mainframe,
the hens first need to ...
- 479
10
votes
1
answer
606
views
How quickly can you convert an NFA to a DFA?
Convert NFA to DFA as quickly as possible.
Input
Your input will be an NFA. In order to be able to test your code, it needs to be able to handle an NFA in the following format. This is taken ...
user9207
9
votes
1
answer
264
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Branch Out - Monkey Edition
The Monkey has swung home to find his tree all in pieces.
He likes order and scoops up all his 'tree-parts' and sets them out in 3 groups.
The Monkey's ...
- 261
1
vote
0
answers
214
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What does the shortest pseudo-random algorithm look like? [closed]
After seeing some impossibly short solutions in this SE, I began to wonder what code someone could come up with to build a pseudo-random number generator. Now given that I am new to programming, I ...
- 19
19
votes
1
answer
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Gerrymander North Carolina
The challenge
How well can you gerrymander North Carolina into 13 voting districts?
In this challenge, you use the following files to draw different maps for Republicans and Democrats.
File 1: ...
- 2,277
36
votes
12
answers
17k
views
The fastest Sudoku solver
Winner found
It seems as if we have a winner! Unless anyone plans on contesting the world's current fastest Sudoku solver, user 53x15 wins with the staggeringly fast solver Tdoku. For anyone still ...
- 6,837
8
votes
6
answers
257
views
Help me sub-divide a time signature
This challenge is based on a video in which Andrew Huang discusses unusual time signatures...
https://www.youtube.com/watch?v=JQk-1IXRfew
In it, he advises that you can understand time signatures by ...
- 11.8k
17
votes
3
answers
536
views
Bridge the Gaps
Given a black and white image with a white background and a set of black dots, paint a set of white pixels red, such that there is a path between each pair of black pixels.
Details
A path is a set ...
- 43.7k
37
votes
11
answers
1k
views
There's an echo in my array... echo in my array... my array
Help! I seem to have an annoying echo in some of my arrays, and I'd like to get rid of it. When this occurs, the original array repeats itself somewhere in the middle causing the values to be added ...
- 11.8k
23
votes
23
answers
4k
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Upside-Down Pyramid Addition...REVERSED! [closed]
Upside-Down Pyramid Addition is the process of taking a list of numbers and consecutively adding them together until you reach one number.
When given the numbers ...
- 355
10
votes
6
answers
2k
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Consistent Overhead Byte Stuffing (COBS)
I'm surprised this hasn't been posted before!
The Consistent Overhead Byte Stuffing (COBS) algorithm is used to delimit byte streams.
We choose a frame marker (we'll use 0x00) and wherever 0x00 ...
- 351
1
vote
2
answers
304
views
Describe a 2D Bitmap Using Filled Rectangle Mapping
Idea:
Consider a 2-bit bitmap of arbitrary side-lengths overlaid on a coordinate grid and imaged with random data (1's represent an element of the image, 0's represent the "blank" canvas background):...
- 113
14
votes
5
answers
388
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Matrix trace for any matrix through... Bresenham’s line rasterisation
Inspired by this.
Agatha Stephendale, a sophomore who is really into raster graphics, has taken a course in linear algebra. Now she imagines matrices as rectangles, but in her artistic mind, she ...
- 1,440
3
votes
0
answers
89
views
lexicographically sorted list of index [closed]
Given a drawing of the letter shoot system, where an existing piece of pipe is marked with a *, and an empty spot is marked with a ., your task is to compile a lexicographically sorted list of index ...
- 39
23
votes
6
answers
2k
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128 years? Hypothetical leap year reform
The solar year is 365 days, 5 hours, 48 minutes, 45 seconds, and 138 milliseconds, according to this video. With the current Gregorian calendar, the rules for leap years are as follows:
...
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3
votes
2
answers
424
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Golfing Newton's Method
I have the following code which I've written to emulate Newton's method for deriving the square root of a number:
...
- 7,493
20
votes
12
answers
4k
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Ethiopian Multiplication
This question is inspired by this answer. Coincidentally, I used to use Ethiopian Multiplication when I was a kid, but had never known the name of the method until recently.
Ethiopian multiplication ...
- 7,493
3
votes
1
answer
1k
views
remove duplicates from array [closed]
You have given an array from which we need to remove duplicates.
Rules:
First or immediate duplicates gets removed first.
Array contains natural numbers ...
- 131
37
votes
21
answers
3k
views
The Original Number
Guidelines
Scenario
John has an important number, and he doesn't want others to see it.
He decided to encrypt the number, using the following steps:
His number is always a non-decreasing sequence (ie. ...
- 1,391
3
votes
6
answers
602
views
Golf Me A Bubble Sort [duplicate]
Your task is to create a program that performs a bubble sort on a given array until it is sorted.
Algorithm
In order to qualify as a bubble sort, the program must operate as follows:
Each pass goes ...
- 1,309
7
votes
2
answers
222
views
Create a version series
The Definition
Given an integer x, a version series is a set of digits (base 10) from which any x-length subset of consecutive ...
- 11.2k
8
votes
4
answers
697
views
Find the rows which make each column have one True (was: Knuth's Algorithm X)
Task
Given a Boolean matrix, find one (or optionally more) subset(s) of rows which have exactly one True in each column. You may use any algorithm, but must support very large matrices, like the last ...
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11
votes
8
answers
727
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Number Triangles
Credit
My thanks to Rand Al'Thor's letter-based question for the inspiration for this code-golf challenge.
Background
The nature of this challenge is based off the algorithm mentioned by Rand in ...
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0
votes
1
answer
351
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The Love Letter Mystery [closed]
At Hackerrank.com, the love letter mystery is a simple programming problem, which I already solved.
My solution involved calculating the palindrome and counting the number of operations to do it. On ...
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