CODEWITHSUNDEEP
rpermutation
Math Avengers
Math Avengers

Reputation: 792

Print all permutations with repetition of characters in r?

I basically want to do the exact same thing as Generating all combinations with unknown length or https://www.geeksforgeeks.org/print-all-permutations-with-repetition-of-characters/ but in R. These links show how to do it in C++ but not R.

Suppose I have letter "ABCD", how to print all permutations with repetition of characters in r?

Upvotes: 0

Views: 334

Answers (2)

Ronak Shah
Ronak Shah

Reputation: 388972

Using gtools::permutations :

string <- 'ABCD'
vec <- strsplit(string, '')[[1]]
result <- gtools::permutations(length(vec), length(vec), vec, repeats.allowed = TRUE)

head(result)
#     [,1] [,2] [,3] [,4]
#[1,] "A"  "A"  "A"  "A" 
#[2,] "A"  "A"  "A"  "B" 
#[3,] "A"  "A"  "A"  "C" 
#[4,] "A"  "A"  "A"  "D" 
#[5,] "A"  "A"  "B"  "A" 
#[6,] "A"  "A"  "B"  "B"

Upvotes: 2

lroha
lroha

Reputation: 34416

One option would be to use the RcppAlgos package although there are at least a handful of other packages that have functions for this:

library(RcppAlgos)

res <- permuteGeneral(LETTERS[1:4], 4, TRUE)

head(res)

     [,1] [,2] [,3] [,4]
[1,] "A"  "A"  "A"  "A" 
[2,] "A"  "A"  "A"  "B" 
[3,] "A"  "A"  "A"  "C" 
[4,] "A"  "A"  "A"  "D" 
[5,] "A"  "A"  "B"  "A" 
[6,] "A"  "A"  "B"  "B" 

nrow(res)
[1] 256

Upvotes: 2

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