Combinations with repetitions: Difference between revisions

=={{header|jq}}==

<lang jq>def pick(n):

def pick(n; m): # pick n, from m onwards

if n == 0 then []

elif m == length then empty

elif n == 1 then (.[m:][] | [.])

else ([.[m]] + pick(n-1; m)), pick(n; m+1)

end;

pick(n;0) ;</lang>

'''The task''':

<lang jq> "Pick 2:",

(["iced", "jam", "plain"] | pick(2)),

([[range(0;10)] | pick(3)] | length) as $n

| "There are \($n) ways to pick 3 objects with replacement from 10."

</lang>

{{Out}}

<lang sh>$ jq -n -r -c -f pick.jq

Pick 2:

["iced","iced"]

["iced","jam"]

["iced","plain"]

["jam","jam"]

["jam","plain"]

["plain","plain"]

There are 220 ways to pick 3 objects with replacement from 10.</lang>