santa.R

#' santa(guests) is a function that assigns guests to a "secret santa" gift swap
#' @param guests the vector of partygoers
#' @return a tibble, with <guests> assigned in "to" and "from" columns

library(magrittr)
library(tibble)

santa <- function(guests) {
  n <- length(guests)
  tibble (
    from = guests %>% sample(n),
    to = c(from[-1], from[1])
  ) %>% 
  return()
}
santa(letters[1:10])
#> # A tibble: 10 x 2
#>     from    to
#>    <chr> <chr>
#>  1     e     h
#>  2     h     b
#>  3     b     d
#>  4     d     a
#>  5     a     g
#>  6     g     c
#>  7     c     i
#>  8     i     j
#>  9     j     f
#> 10     f     e