Knuth shuffle: Difference between revisions
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=={{header|SparForte}}==
As a structured script.
<syntaxhighlight lang="ada">#!/usr/local/bin/spar
pragma annotate( summary, "shuffle" );
pragma annotate( description, "Implement the Knuth shuffle (aka the" );
pragma annotate( description, "Fisher-Yates-Durstenfeld shuffle)" );
pragma annotate( description, "for an integer array (or, if possible, an array of any" );
pragma annotate( description, "type). The Knuth shuffle is used to create a random" );
pragma annotate( description, "permutation of an array." );
pragma annotate( description, "Note: spar has a built-in arrays.shuffle() function that does this." );
pragma annotate( see_also, "http://rosettacode.org/wiki/Knuth_shuffle" );
pragma annotate( author, "Ken O. Burtch" );
pragma license( unrestricted );
pragma restriction( no_external_commands );
procedure shuffle is
subtype array_element_type is string;
type magic_items is array(1..3) of array_element_type;
a : magic_items := ( "bell", "book", "candle" );
t : array_element_type;
k : integer;
begin
for i in reverse arrays.first( a ) .. arrays.last( a )-1 loop
k := integer( numerics.rnd( i+1 ) ) - 1 + arrays.first(a);
t := a(i);
a(i) := a(k);
a(k) := t;
end loop;
for i in arrays.first( a ) .. arrays.last( a ) loop
? a(i);
end loop;
end shuffle;</syntaxhighlight>
=={{header|Stata}}==
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