use warnings;
use strict;

my @charges = qw/ch1 ch2 ch3 ch4 ch5 ch6 ch7 ch8 ch1 ch2
                 ch3 ch4 ch5 ch1 ch2 ch6 ch7 ch4 ch3 ch9 ch2 ch4/;

my %bundle1 = map { $_ => 0 } qw(ch3 ch4 ch6);

for (@charges) {
    if (exists $bundle1{$_}) {
        print "chx ";
    }
    else {
        print "$_ ";
    }
}
print "\n";


__END__

ch1 ch2 chx chx ch5 chx ch7 ch8 ch1 ch2 chx chx ch5 ch1 ch2 chx ch7 chx chx ch9 ch2 chx