Knuth shuffle: Difference between revisions
Add CLU
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vect (range (dec (count vect)) 1 -1)))</lang>
This works by generating a sequence of end-indices from n-1 to 1, then reducing that sequence (starting with the original vector) through a function that, given a vector and end-index, performs a swap between the end-index and some random index less than the end-index.
=={{header|CLU}}==
<lang clu>knuth_shuffle = proc [T: type] (a: array[T])
lo: int := array[T]$low(a)
hi: int := array[T]$high(a)
for i: int in int$from_to_by(hi, lo+1, -1) do
j: int := lo + random$next(i-lo+1)
temp: T := a[i]
a[i] := a[j]
a[j] := temp
end
end knuth_shuffle
start_up = proc ()
po: stream := stream$primary_output()
d: date := now()
random$seed(d.second + 60*(d.minute + 60*d.hour))
arr: array[int] := array[int]$[1,2,3,4,5,6,7,8,9]
knuth_shuffle[int](arr)
for i: int in array[int]$elements(arr) do
stream$puts(po, int$unparse(i) || " ")
end
end start_up</lang>
{{out}}
<pre>7 9 2 3 4 8 1 6 5</pre>
(Or any other order.)
=={{header|CMake}}==
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