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my $pchr = "KQRBNP"; my $w1 = "QRKPNBNBQRK"; ... } print "$w1 -> $w2\n"
my $pchr = "KQRBNP"; my $w1 = "QRKPNBNBQRK"; ... $w1 =~ m/^(?:$re)(?<=(.))(?{ $w2 .= $1 })(*FAIL)/; print "$w1 -> $w2\n"