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my ($i1) = grep { $array[$_] == 1 } 0..$#array; my ($i2) = grep { $array[$_] == 2 } 0..$#array; my ($i3) = grep { $array[$_] == 3 } 0..$#array;
my %lookup = map { $array[$_] => $_ } 0..$#array; my $i1 = $lookup{1}; my $i2 = $lookup{2}; my $i3 = $lookup{3};