Re: Randomly outputting an array

Richard Heathfield wrote:
ryanarossi@xxxxxxxxx said:

What would be the simplest way to output an array in random order, but
every element in the array MUST be outputted and the elements cannot
repeat? My current code is below, which I simply have a very large
array and I am outputting windows of an arbitary length.

OPTION BASE 0

DIM DECK(52) AS INTEGER
DIM N AS INTEGER
DIM R AS INTEGER
DIM T AS INTEGER

N = 52

REM Populate array
FOR J = 0 TO N - 1 STEP 1
DECK(J) = J
NEXT

REM Display in original order
FOR J = 0 TO N - 1 STEP 1
PRINT J;" ";
NEXT
PRINT

REM Shuffle
FOR J = 0 TO N - 1 STEP 1
R = INT(RND * (N - J)) + J
T = DECK(R)
DECK(R) = DECK(J)
DECK(J) = T
NEXT

REM Display in shuffled order
FOR J = 0 TO N - 1 STEP 1
PRINT J;" ";
NEXT
PRINT

END

Converting to a sensible language is left as an exercise.

#!/usr/bin/perl
use warnings;
use strict;

sub shuffle {
my $deck = shift;
my $i = @$deck;
while ( $i-- ) {
my $j = int rand( $i + 1 );
@$deck[ $i, $j ] = @$deck[ $j, $i ];
}
}

# Populate array
my @deck = 0 .. 51;

# Display in original order
print "@deck\n";

# Shuffle
shuffle \@deck;

# Display in shuffled order
print "@deck\n";

__END__



John
--
use Perl;
program
fulfillment
.

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