Perl技巧 两个数组的取交集，并集与补集

利用perl 对两个数组进行操作。 目的是取2个数组只属于各自的元素，以及2个数组的共同元素。（可见下图）

代码：

#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

my @a = (1,2,3,4,5,6,7,8,);
my @b = (1,9,15,12,8);
my %hash_a = map{$_=>1} @a;
my %hash_b = map{$_=>1} @b;
my %merge_all = map {$_ => 1} @a,@b;
my @a_only = grep {!$hash_b{$_}} @a;
my @b_only = grep {!$hash_a{$_}} @b;
my @common = grep {$hash_a{$_}} @b;
my @merge = keys (%merge_all);
print "A only :n";
print Dumper(@a_only);
print "B only :n";
print Dumper(@b_only);
print "Common :n";
print Dumper(@common);
print "Merge :n";
print Dumper(@merge);

运行结果 ：

dxxu@rlsj-dxxu:/home/dxxu>{76}perl array_operation.pl
A only :
$VAR1 = [
          2,7
        ];
B only :
$VAR1 = [
          9,12
        ];
Common :
$VAR1 = [
          1,8
        ];
Merge :
$VAR1 = [
          '6','3','7','9','12','2','15','8','1','4','0','5'
        ];