Questions tagged [restricted-time]
For challenges with a restriction on the amount of time a submission is allowed to use.
92
questions
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10
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Find the longest permutations of integers from 1..k such that all neighbouring pairs sum to a square
OEIS A090461 details the ‘numbers k for which there exists a permutation of the numbers 1 to k such that the sum of adjacent numbers is a square’. This has also been the subject of Matt Parker’s ...
- 17k
8
votes
2
answers
270
views
Implement Level-Index Addition
Level-index is a system of representing numbers which has been proposed as an alternative to floating-point formats. It claims to virtually eliminate overflow (and underflow, in its symmetric form) ...
- 19.4k
8
votes
1
answer
417
views
Next Special String
Special String
We call a binary string \$S\$ of length \$N\$ special if :
substring \$S[0:i+1]\$ is lexicographically strictly smaller than substring \$S[i+1:N]\$ for \$ 0\leq i\leq N-2\$,
Note: \$ ...
- 619
5
votes
0
answers
233
views
Find the best character arrangement
You want to write your English essay. However, all characters on your keyboard broke other than the arrow keys and the enter key. You want to find out how to place the characters so you can write your ...
- 7,448
17
votes
3
answers
1k
views
Solve Rubik's Clock
Rubik's Clock is a round(ish) puzzle with two flat sides. On each side, front and back, there are 9 clock faces, arranged on a 3x3 grid. In addition, there are 4 pegs (switches) in between the clock ...
- 6,846
8
votes
1
answer
216
views
Is this a Hamiltonian cycle?
There is a 3x3 square block made of 1x1 square blocks, with coins in each 1x1 block, starting from top left block you want to collect all the coins and return to top left block again, if possible ...
- 619
-4
votes
3
answers
508
views
Code golf edit distance up to 3 [duplicate]
The edit distance between two strings is the minimum number of single character insertions, deletions and substitutions needed to transform one string into the other.
This task is simply to write code ...
user7467
20
votes
12
answers
3k
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Fastest draw in the west! [closed]
We're going rootin' tootin' cow-poke shootin!
This is a simple contest, first program to draw their pistol wins.
How it works:
I require 2 things from you, an executable, and a command to be run
from ...
- 3,825
23
votes
5
answers
1k
views
Can this pattern be made with dominoes?
Given a pattern of squares on a grid, determine if it is possible to create that pattern with non-overlapping dominoes. In case you are not familiar, a domino is a rectangular shape created by joining ...
- 9,861
20
votes
9
answers
621
views
Zeroes at end of \$n!\$ in base \$m\$
Related: Zeroes at the end of a factorial
Today, we are going to calculate how many zeroes are there at the end of \$n!\$ (the factorial of \$n\$) in base \$m\$.
Or in other words: For given integers \...
- 33.6k
11
votes
10
answers
810
views
Find the number of ways to climb a stairway
Challenge:
Find the number of ways to climb some stairs with n steps and with some limitations. You should be able to run the tests below on TIO https://tio.run/ without timing out. – 60 seconds. (...
- 5,357
24
votes
9
answers
918
views
Animal-Alphabetical Sequence
The Animal-Alphabetical Sequence is an infinite string of letters built accordingly to the following procedure:
Start with the letter A;
Replace each letter with ...
- 248
13
votes
7
answers
709
views
Iterate over the neighborhood of a string
Input
A string S of length between 2 and 30. The only letters in the string will be a or b.
Output
All strings within ...
user7467
15
votes
10
answers
2k
views
When does hh:mm = mm.ss?
Let's begin with a thought experiment. You have a clock and a timer, in which you start the timer when the clock shows exactly hh:mm.00.
Clock: The clock employs ...
user92069
11
votes
4
answers
394
views
Holey Knight's Tour
Given a rectangular board of cells with some number of holes in it, determine whether it is possible to complete a "holey knight's tour" (That is, a path that visits every non-hole cell exactly once ...
- 9,861
20
votes
2
answers
378
views
Exactly N in a line
Given a number N from 2 to 8, place any nonzero number of queens on a grid of any size so that every queen has exactly N queens (counting itself) in each of its row, column, and each diagonal.
This ...
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11
votes
2
answers
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views
Are these two DFAs equivalent?
Two Deterministic Finite Automata or DFAs can be checked to see if they accept same set of strings in polynomial time. See section 3.3 of this for a long list of methods and this SO question/answer ...
user9207
2
votes
5
answers
192
views
Shift the digits [closed]
Here, x (supplied as input) and n (the result of your computation) are both positive integers. n * x = n shifted. Find n.
Here's an example of shifting:
...
user92069
5
votes
3
answers
407
views
Choose 3 strings and output the exact minimum Hamming distance between any pair
Consider \$3\$ binary strings of length \$n\$ chosen independently and uniformly at random. We are interested in computing the exact expected minimum Hamming distance between any pair. The Hamming ...
user9207
19
votes
2
answers
708
views
Counting creatures on a hexagonal tiling
This challenge will have you count "creatures" in the tile game Palago.
A creature is any closed shape that can be formed by Palago tiles of matching colour in a hexagonal grid.
The game Palago ...
- 8,649
7
votes
4
answers
678
views
Find X,Y,Z coordinates from index
Introduction
I began studying the Collatz Conjecture
And noticed these patterns;
0,1,2,2,3,3...A055086, and 0,1,2,0,3,1...A082375,
in the numbers that go to 1 in one odd step,
5,10,20,21,40,42......
- 743
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votes
5
answers
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views
Report divisibility with arithmetic integer operations only [closed]
Given two numbers, the first is greater than the second, check whether the first number is divisible by the second without a remainder. If divisible, answer "yes"(...
- 101
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votes
4
answers
1k
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Output first \$n\$ digits of \$\pi^{1/\pi}\$
This challenge is to produce the shortest code for the constant \$\pi^{1/\pi}\$. Your code must output the first \$n\$ consecutive digits of \$\pi^{1/\pi}\$, where \$n\$ is given in the input. ...
user9207
11
votes
6
answers
1k
views
Which really big number is bigger?
This question is tricky (and in particular harder than Which big number is bigger?), for those who like more challenging puzzles.
Input
Integers a1, a2, a3, a4, a5, b1, b2, b3, b4, b5 each in the ...
user9207
9
votes
10
answers
908
views
Next number with k fives
Challenge:
Your program will take two integers n and k as input, and output the smallest integer greater than (but not equal to)...
- 487
17
votes
3
answers
1k
views
Plight of the Concorde
Background
The traveling salesman problem (TSP) asks for the shortest circuit that visits a given collection of cities. For the purposes of this question, the cities will be points in the plane and ...
- 2,559
18
votes
10
answers
2k
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Reciprocal copycats
Let \$A\$ be a positive integer consisting of \$n\$ decimal digits \$d_1,d_2,...,d_n\$. Let \$B\$ be another positive integer.
For the purpose of this challenge, we call \$A\$ a copycat of \$B\$ if ...
- 186k
23
votes
23
answers
4k
views
Encode - Shuffle - Decode
Challenge
Your task is to encode an integer as a string of ASCII characters, then successfully decode it after said string has been randomly shuffled.
You will write two programs/functions, which ...
- 6,236
9
votes
0
answers
461
views
The N Queens Problem, but with Fairy Chess Pieces
Fairy Chess is a sort of generalized chess that allows unconventional pieces. The eight queens puzzle is a classic problem where you have to put 8 queens on a chess board such that no two queens ...
- 9,861
21
votes
11
answers
2k
views
Fruit bagging factory
Your mission is to build an algorithm (program or function) that can optimize packing fruit from a conveyor belt into bags to be sent off to retailers, optimizing for a largest number of bags.
Each ...
- 4,957
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 ...
- 15.2k
11
votes
2
answers
2k
views
Solve a Rubik's Cube
Your challenge is to write a program to solve a 3x3x3 Rubik's Cube. This challenge is based on this one from 2013, rewritten to adhere to current community standards, and reposted with the original ...
- 13.7k
10
votes
6
answers
831
views
Output all distinct permutations of a vector
Challenge:
Output all distinct permutations of a, potentially long, list of positive integers. You may assume that the vector has less than 1,000 numbers when testing, but the process should in ...
- 46.1k
19
votes
7
answers
2k
views
Number of distinct non-empty subsequences of binary expansion
A subsequence is any sequence that you can get from another by deleting any amount of characters. The distinct non-empty subsequences of 100 are ...
- 39k
34
votes
6
answers
3k
views
Finding Snakes in a Matrix
Challenge
Given a binary matrix and a binary string, determine if that binary string can be found starting at any point in the matrix and moving in any direction at any subsequent point to form the ...
- 41.1k
23
votes
28
answers
2k
views
Count forth and back then double up
Let's count...
Count up to 2 and back to 1
Count up to 4 and back to 1
Count up to 6 and back to 1
... ok you got it...
put all these together and you'll get the following sequence
...
user73398
55
votes
14
answers
8k
views
Extreme Fibonacci
There have been a billion iterations of Fibonacci challenges on this website, so lets spice things up with a Fibonacci challenge of a billion iterations!
Your challenge is to output the first 1000 ...
- 3,559
19
votes
6
answers
1k
views
Fastest tweetable integer factorizer
The task is to find a non-trivial factor of a composite number.
Write code that finds a non-trivial factor of a composite number as quickly as possible subject to your code being no more than 140 ...
user9206
15
votes
4
answers
1k
views
Square root a number
The task is as follows: Given a positive integer x and a prime n > x, output the smallest positive integer ...
user9206
21
votes
9
answers
4k
views
Compute the inverse of an integer modulo 100000000003
The task is the following. Given an integer x (such that x modulo 100000000003 is not equal ...
user9206
12
votes
2
answers
635
views
Find a number which generates all the integers mod q
Consider the integers modulo q where q is prime, a generator is any integer 1 < x < q ...
user9206
16
votes
2
answers
378
views
Output a primitive element for each field size
A primitive element of a finite field is a generator of the multiplicative group of the field. In other words, alpha in F(q) is ...
user9206
14
votes
7
answers
899
views
39
votes
18
answers
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views
11 = (1+2+3+4+5) - (1+2+3) + (6) - (4)
Given a positive integer N, your task is to return the number of steps required by the following algorithm to reach N:
Find the smallest triangular number Ti such that Ti ≥ N. Build the ...
- 186k
23
votes
2
answers
963
views
Optimize sorting, using "Sub-vector reversals"
This is a fewest-operations challenge where the objective is to sort a vector into ascending order using the fewest reversals. Your algorithm can only sort the vector using "sub-vector reversals"1, ...
- 46.1k
28
votes
19
answers
2k
views
Find the sortable years
The year 2013 had an interesting property: the digits are consecutive when sorted (0123). Let's call this type of number a sortable number: a non-negative integer whose base-10 digits are consecutive ...
- 49.9k
21
votes
3
answers
2k
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Piet (Mondrian)'s Puzzle
For more information, watch this video, and go to A276523 for a related sequence.
The Mondrian Puzzle (for an integer n) is the following:
Fit non-congruent ...
- 6,972
24
votes
6
answers
1k
views
Fraction to exact decimal
Write a program or function that given two integers a, b outputs a string containing a decimal number representing the fraction a/b exactly.
If a/b is integer, simply output the value, without a ...
- 39k
44
votes
69
answers
4k
views
Fibonacci-orial
Definition
Fibonacci sequence F(n), on the positive integers, are defined as such:
...
- 49.5k
67
votes
9
answers
5k
views
Addition in base -1+i
Gaussian integers are complex numbers of the form a+bi where a and b are both integers. In ...
- 61.7k