Questions tagged [permutations]

A permutation is a particular ordering of some list of objects. Problems tagged with permutation usually involve finding or generating permutations, including anagrams of text.

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6
votes
4answers
736 views

Find imperfect anagrams

The goal of this challenge is to write a program which takes a string (of any length) as input and displays anagrams (see these examples of anagrams) of this string, made by taking words in a ...
16
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2answers
4k views

Solve the (Rubiks) Pocket Cube

Your task .. is to do what Brian Fantana apparently couldn't do, and solve the 2x2x2 Rubik's Cube. The Layout ...
20
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5answers
919 views

Draw a Permutation Path

Imagine the following diagrams as sets of vertical criss-crossing tubes. ...
9
votes
6answers
803 views

Permutation Numbering

The Challenge For a given set of n integers, write a program which will output its lexicographic index. The Rules The input must only be a set of unique non-negative integers separated by spaces. ...
74
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11answers
11k views

The 9 Billion Names of God

The 9 Billion Names of God is a short story by Arthur C. Clarke. It's about a group of Tibetan monks whose order is devoted to writing down all the possible names of God, written in their own alphabet....
3
votes
3answers
391 views

Find the next subpermutation of base-64 digits

Permutations of a set have a natural order called lexicographic order in which two permutations are compared by comparing the first position at which they differ. For the purposes of this question we'...
4
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4answers
2k views

Obtaining ordering of cards [closed]

You are given a deck containing n cards. While holding the deck: Take the top card off the deck and set it on the table Take the next card off the top and put it on the bottom of the deck in your ...
18
votes
14answers
1k views

The Strange Unsorting Machine for Nefarious Purposes

Good Evening Golfers! Your challenge is to completely unsort a series of numbers. Input Exactly 100 integers will be fed to your program. Your program may accept the input either as a file, or via ...
21
votes
25answers
2k views

Code-Golf: Permutations

Write a function that takes as input a set of integers (can be a list, array or any other container with distinct numbers), and outputs the list of all its permutations. Python (95 chars): ...
15
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6answers
2k views

Decompose a permutation into cycles

There is a well-known theorem that any permutation can be decomposed into a set of cycles. Your job is to write the shortest possible program to do so. Input: Two lines. The first contains a ...
14
votes
3answers
476 views

Permutation group operation

There is a well-known bijection between the permutations of n elements and the numbers 0 to n!-1 such that the lexicographic ordering of the permutations and the corresponding numbers is the same. For ...
85
votes
133answers
11k views

Determine whether strings are anagrams

Challenge Given two strings, work out if they both have exactly the same characters in them. Example Input word, wrdo This returns true because they are the ...