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Dirty Arrays and how to clean them up!

I have this array with duplicate entries. Hundreds to be in fact.

For example:Array = 17177 9661 9661 9535 9533 9533 9533 9533 9533 9533
9533 9533 9533 9533 9533 9533 9533 9533 9532 9532 9532 9532 9531 9096
9096 9096 9095 9095 9095 8345 8345 8344 8344 8226 8226 8225 8225 8198
8198 8198 8198 8198 8198 8198 8198 8198 8198 8198 8198 8198 8198 8198
8198 8198 8198 8198 8198 8198 8198 8198 8198 8198..............

This is what i am doing. i am reading file1 that has these entries in
the file mutiple times. I am comparing it against file2. if i do not
find a match i write the record to file3 and then to an array. when i
read file1 again and compare it against file2 i check to see if the
recorrd has been written by rereading the array and looking for it.
if it finds the same entry in the array then read the next record do
not wirte to file3. if not then write the record to file3 and the
array.

i either want to only write once to the array per record or before i
check remove dupliactes.

here some code example:
while file1
while file2
if record1 != record2
if record2 is not in array
write to file3
write to new record to array
last
else
next
else
next

Here is another example that
shows a poor example but you should get the idea. at least i
hope!!!!

@SORTED = ();
@CLEANED = ();
$X = 0;
$R = 0;
while ($R < 4)
{
while ($X <= 100)
{
$X++;
# print "I am in X\n";
# # i really do not want to write to the array if
# # it already exists in the array.
# # if array already has X then do not right to the
# # array.
push @CHECKED, $X;
@SORTED = sort {$a <=> $b} @CHECKED;
}
# print "*********I am in R\n";
$R++;
$X = 0;
next;
}

print "Array = @SORTED\n";

foreach $Row (@SORTED)
{
$Hold = $Row;
if ($Hold == $Row)
{
@CLEANED = shift @SORTED;
}
else
{
next;
}
# # How do i remove duplicates from the array?
# # I know this is wrong but here is my delima!
}

print "Array = @CLEANED\n";

Jul 19 '05 #1
4 6784
Bob
I have been working on the solution myself, but i am still having
problems. Here is where I am so far!

Still lost!

@SORTED = ();
@CLEANED = ();
$X = 0;
$R = 0;
while ($R < 4)
{
while ($X <= 100)
{
$X++;
# print "I am in X\n";
# # i really do not want to write to the array if
# # it already exists in the array.
# # if array already has X then do not right to the
# # array.
push @CHECKED, $X;
@SORTED = sort {$a <=> $b} @CHECKED;
}
# print "*********I am in R\n";
$R++;
$X = 0;
next;
}

print "Array = @SORTED\n";

$Element2 = 0;

for ($Element1 = 0; $Element1 < @SORTED; $Element++)
{
$Element2 = ($Element1 + 1);
if ($SORTED[$Element1] == $SORTED[$Element2])
{
print "$SORTED[$Element1] == $SORTED[$Element2]\n";
delete $SORTED[$Element2];
$Element1--;
next;
}
else
{
next;
}
}
# # How do i remove duplicates from the array?
# # I know this is wrong but here is my delima!

print "Array = @CLEANED\n";

Jul 19 '05 #2
Bob
Sorry i cut and pasted only half of the code!

@SORTED = ();
@CLEANED = ();
$X = 0;
$R = 0;
while ($R < 4)
{
while ($X <= 100)
{
$X++;
# print "I am in X\n";
# # i really do not want to write to the array if
# # it already exists in the array.
# # if array already has X then do not right to the
# # array.
push @CHECKED, $X;
@SORTED = sort {$a <=> $b} @CHECKED;
}
# print "*********I am in R\n";
$R++;
$X = 0;
next;
}

print "Array = @SORTED\n";

$Element2 = 0;

for ($Element1 = 0; $Element1 < @SORTED; $Element++)
{
$Element2 = ($Element1 + 1);
if ($SORTED[$Element1] == $SORTED[$Element2])
{
print "$SORTED[$Element1] == $SORTED[$Element2]\n";
delete $SORTED[$Element2];
$Element1--;
next;
}
else
{
next;
}
}
# # How do i remove duplicates from the array?
# # I know this is wrong but here is my delima!

print "Array = @CLEANED\n";

Jul 19 '05 #3
bob

the easiest way to do this is to use all elements of your dirty as keys
to a hash. there are shorter forms to this solution, but i'll leave it
verbose for clarity;

hope this helps

-r

################################################## #############
# see
# http://perlmonks.com/index.pl?node=609
# for reference
################################################## #############

use strict;

my @dirty = ( 1, 2, 3, 2, 3, 4, 9, 8, 7, 6, 5, 4, 3, 2, 1);
#
# the hash we will use to track unique elements in @dirty
#
my %occurred;
foreach my $dirtyElement ( @dirty )
{
$occurred{$dirtyElement} = 1;
}
#
# we can now retrieve the unique elements from %occurred
#
my @unique = keys %occurred;

print @unique;

################################################## #############


"Bob" <sp***@realconsultants.com> wrote in news:1109737474.473572.207520
@g14g2000cwa.googlegroups.com:
Sorry i cut and pasted only half of the code!

@SORTED = ();
@CLEANED = ();
$X = 0;
$R = 0;
while ($R < 4)
{
while ($X <= 100)
{
$X++;
# print "I am in X\n";
# # i really do not want to write to the array if
# # it already exists in the array.
# # if array already has X then do not right to the
# # array.
push @CHECKED, $X;
@SORTED = sort {$a <=> $b} @CHECKED;
}
# print "*********I am in R\n";
$R++;
$X = 0;
next;
}

print "Array = @SORTED\n";

$Element2 = 0;

for ($Element1 = 0; $Element1 < @SORTED; $Element++)
{
$Element2 = ($Element1 + 1);
if ($SORTED[$Element1] == $SORTED[$Element2])
{
print "$SORTED[$Element1] == $SORTED[$Element2]\n";
delete $SORTED[$Element2];
$Element1--;
next;
}
else
{
next;
}
}
# # How do i remove duplicates from the array?
# # I know this is wrong but here is my delima!

print "Array = @CLEANED\n";


Jul 19 '05 #4
Here is my attempt:

my %temp = ();
print grep !$temp{$_}++, ((1..10) x 5);

....which is essentially the same concept as you described, but just a
different approach.

Jul 19 '05 #5

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