push(@arrCompletedChains, $strChain);

##</code><code>##

    If any part of LIST is an array, "foreach" will get very
    confused if you add or remove elements within the loop
    body, for example with "splice".   So don't do that.

##</code><code>##


use List::Util 'first';

# sort largest first
my @sorted = sort { length $b <=> length $a } @arrWorkingCompletedChains;
my %to_delete;
# remove shortest first
while ( my $next = pop @sorted ) {
    if ( first { index( $_, $next ) >= 0 } @sorted ) {
        ++$to_delete{ $next };
        }
    |

@arrWorkingCompletedChains = grep !$to_delete{ $_ }, @arrWorkingCompletedChains;