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I have a loop here, that is requiring a lot of time to run. (I believe) The purpose is to read an edge list and convert it into a hash, there's about 30,000 nodes in this graph, but 90,000 lines. So there are loops which need to be eliminated. (Graph is undirected.) The data is such that:
0 1
1 2
1 3
1 4
2 4
4 5

With my code looking like:
my %edgeHash; my %countHash; while(<stdin>){ # Reading an edge list if(/^\s*([0-9]+)\s+([0-9]+)\S*$/){ my $a = "$1"; my $b = "$2"; my $good = "1"; # Eliminate loops foreach my $item (keys %edgeHash){ foreach my $item2(@{$edgeHash{$item}}){ if($item2 eq $b){ $good = "0"; } } } # Add items to the edge hash if($good eq "1"){ if(exists($edgeHash{$a})){ push @{$edgeHash{$a}}, $b; }else{ push @{$edgeHash{$a}}, $b; } } } }

In reply to H of A optimization by abitkin

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