input file:
mylist_1  sublist_153  sublist_87  sublist_876  sublist_78
mylist_6  sublist_8
mylist_2  sublist_12  sublist_34  sublist_09
mylist_3  sublist_87  sublist_09
mylist_7  sublist_8  sublist_9
mylist_9  sublist_56 

in the above example, line 2 is a substring of line5. since line5 is longer than line2, only only line5 is taken for results. another example is line4 is a substring of line3, since line3 is longer, i take only that for results.

another example:
apple orange cake juice
apple fruits
car van bus jeep
sumo hat
people van car

in the above example, apple in found in 2 lines, but i keep only the line which has many elements compared the other. car is found in last line and 3rd line. but i take only the 3rd line as hit because it has many elements compared to last line. 

so my result would be:
apple orange cake juice
car van bus jeep
sumo hat



my program:
#!/usr/bin/perl
open(FH,"input_file.txt") or die "can not open input file";

while($line=<FH>){
@collect=split(/\s+/,$line);
push(@aoa,join("#",@collect));
}

my %h;
for(@aoa){
 push(@uaoa,$_ if !$h{join $;, @$_}++;
}

foreach(@uaoa){
print "$_\n";
}

the desired output for this problem:
mylist_1  sublist_153  sublist_87  sublist_876  sublist_78
mylist_7  sublist_8  sublist_9
mylist_2  sublist_12  sublist_34  sublist_09
mylist_9  sublist_56