RosettaCodeData/Task/Knuth-shuffle/R/knuth-shuffle-2.r
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2013-04-10 12:38:42 -07:00

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R

fisheryatesknuthshuffle <- function(n)
{
a <- seq_len(n)
while(n >=2)
{
k <- sample.int(n, 1)
if(k != n)
{
temp <- a[k]
a[k] <- a[n]
a[n] <- temp
}
n <- n - 1
}
a
}
#Example usage:
fisheryatesshuffle(6) # e.g. 1 3 6 2 4 5
x <- c("foo", "bar", "baz", "quux")
x[fisheryatesknuthshuffle(4)] # e.g. "bar" "baz" "quux" "foo"