use strict;
my @array=(1,2);

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

print "<$i1> <$i2> <i3>\n";