Hi

quick question , is there a faster alternative for the push and shift function on the following code:

my @a =();
my @b =();

while(<IN>){
  chomp;
  $cnt++;
  /\d+\t(\d+)/;
  if (@a<7){
    push(@a,$1);
  }
  push(@b,$1) if $1 > 3;
  if (@b>7){
    shift(@a);
    shift(@b);
  }
  print $a[0] - $b[-1] . "\n"
}

[download]
the reason i'm asking is because if i just iterate through file IN like : 
while(<IN>){
  $cnt++
}

[download]
it takes me 10 min and if a complicate it with 2 push and shift functions, plus regex, the runtime increases to 150 min

cheers

baxy

Update:

ok so more details , though i think they are irrelevant: 


file size: 70GB
file format :  tsv

1     34
2     6
3     78

simple while-loop time:  

real    10m51.378s
user    9m22.610s
sys    0m13.120s



while loop with regex + push and shift + one subtraction(i forgot to m
+ention that)

real    157m13.245s
user    152m8.520s
sys    1m26.660s

[download]

In reply to Faster push and shift by baxy77bax

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