Perl uses grep map to find the intersection, set, and complement instance code _perl

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#!/usr/bin/perl
#
# using grep map to get the intersection and set of two lists, the complement
#
Use strict;
My @a= ("a", "B", "C", "D", "E");
My @b= ("B", "G", "F", "E");
Print "List a data: @a \ n";
print "List B data: @b \ n";
My%a = map{$_ => 1} @a;
My%b = map{$_ => 1} @b;
My @c = map{$_ => 1} @a; # The => operator plays the role of hash assignment
# @a @b Intersection
My @inter = grep {$a {$_}} @b; # Find the Intersection
Print "intersection: @inter \ n";
# @a,@b and set
My%merge = map {$_ => 1} @a,@b; # Seek and set
My @merge = keys (%merge);
Print "and set: @merge \ n";
# @a,@b's complement @ca, @cb, that is @a and @b, relative to @merge's complement
My @ca = grep {! $a {$_}}} @merge;
My @cb = grep {! $b {$_}}} @merge;
Print "\@a's complement: @ca \ n";
Print "\@b's complement: @cb \ n";