# Usage:
# ./permute.sh r x1 x2 x3 ... xn

# Example:
# ./permute.sh 2 a b c
# a a
# a b
# a c
# b a
# b b
# b c
# c a
# c b
# c c

set -e

n=$(( $# - 1 ))
r=$1

shift # skip first argument

cmd="parallel echo "

for i in $(seq 1 $r); do
    cmd="$cmd ::: $@"
done

$cmd