Questions tagged [counting]
For challenges regarding counting the number of occurrences of some characteristic.
130 questions
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3
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Count number of families of sets satisfying a list of criteria
CHALLENGE
This problem has a math background.
For n=1,2,3,4 we want to count the number of families of sets with maximum n elements that satisfy many criteria of the form:
$$\bigoplus_{k\in A,A\in \...
17
votes
20
answers
2k
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Number of legal positions in 1D go
A 1D go position on a board of size n is a sequence of length n consisting of the numbers0, <...
33
votes
21
answers
3k
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Count the fish in a school
Go Fish!
Given a school of fish, for example:
...
7
votes
12
answers
815
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Counting constrained permutations
Challenge:
Write a program or function that, given positive integers n, t, b, c, counts permutations of 1..n where:
Exactly t numbers are in their original position
Exactly b numbers are higher than ...
-1
votes
1
answer
189
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Golomb's self-describing sequence problem [duplicate]
Inspired by this problem.
Golomb's self-describing sequence g(n) is a sequence where any natural number n is repeated within the sequence g(n) times.
Given an input of \$ n \,ドル output: $$ \left( \sum_{...
16
votes
17
answers
1k
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Count N-Rich Permutations of an Integer Sequence
Given a sequence of integers with length \$L\$ and an integer \1ドル \le N \le L\,ドル an "\$N\$-rich" permutation is one whose the longest strictly increasing contiguous subsequence has length ...
31
votes
50
answers
3k
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Replace 0s In a String With Their Consecutive Counts
Challenge
Given a string of any length which contains only digits from 0 to 9, replace each consecutive run of the digit ...
28
votes
49
answers
3k
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Count /[^a-z]/ig with /[a-z]/ig
Write a program or function which takes a string of text as input and outputs the number of non-alphabetical characters in it (standard I/O rules apply). A non-alphabetical character is any character ...
10
votes
1
answer
416
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Counting overlapping objects
Consider a NxN pixel grid with up to M objects drawn on it, either squares or diamonds:
square
diamond
The objects may overlap, so recognition is hard. The task is to give the minimal possible ...
16
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14
answers
1k
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Count count count
Description
You have a list of integers and start counting from the first term to the next and continue from that to the next and so on..
How many times have you counted?
For example given [ 2, 5, 3, ...
34
votes
30
answers
2k
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Converge to a number
Your challenge is to, given a positive integer n, count up to each digit of it, giving the effect of converging on it.
Basically, count up to the first digit of n by its place value (\$⌊\log_{10}\left(...
22
votes
36
answers
2k
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Return all letter counts as an integer
Definition
Given some string return an integer whose digits are the number ocurrences of a-z (case insensitive, in alphabetical order) in that string. Any character with 0 instances is skipped. ...
19
votes
2
answers
648
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Counting and so on
Content
You count numbers every day (I think), and most of you know how to count properly, the one next to 1 is 2, and the next ...
15
votes
12
answers
2k
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How many Sets are there?
This is similar in concept to this challenge, but that is pretty restrictive on input and output and I think opening up these restrictions would lead to a completely different set of solutions that ...
33
votes
55
answers
2k
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Replace all items with their counts
Task:
Given an array of numbers as input (you can choose what subset, such as integers or natural numbers), replace all items with the number of times they appear within the array. As an example, <...