Re: Random Derangement Of An Array


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Re: Random Derangement Of An Array

by jacques (Priest)

on Jul 06, 2008 at 03:47 UTC ( #695780=note: print w/replies, xml )

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in reply to Random Derangement Of An Array

sub fisher_yates_shuffle {
        my $deck = shift;  # $deck is a reference to an array
        my $i = @$deck;
        while ($i--) {
            my $j = int rand ($i+1);
            @$deck[$i,$j] = @$deck[$j,$i];
        }
    }

my @list = (1..5);
fisher_yates_shuffle( \@list );
print join ', ',@list;
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Re^2: Random Derangement Of An Array by Limbic~Region (Chancellor) on Jul 06, 2008 at 04:12 UTC
jacques, Is this a modified Fisher-Yates shuffle? I am too tired to tell. If it isn't, then it won't work because a shuffle is not guaranteed to generate a derangement. If it is - please explain the modification. Cheers - L~R	[reply]

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