perl用grepmap求交集、并集、补集的实例代码

#!/usr/bin/perl
#
#用grepmap获取两个列表的交集并集、补集
#
usestrict;
my@a=("a","b","c","d","e");
my@b=("b","g","f","e");
print"列表a数据：@a\n";
print"列表b数据:@b\n";
my%a=map{$_=>1}@a;
my%b=map{$_=>1}@b;
my@c=map{$_=>1}@a;    #=>操作符起到了hash赋值的作用
#@a@b交集
my@inter=grep{$a{$_}}@b;    #求交集
print"交集：@inter\n";
#@a,@b并集
my%merge=map{$_=>1}@a,@b; #求并集
my@merge=keys(%merge);
print"并集：@merge\n";
#@a,@b的补集@ca，@cb，即@a和@b相对于@merge的补集
my@ca=grep{!$a{$_}}@merge;
my@cb=grep{!$b{$_}}@merge;
print"\@a的补集:@ca\n";
print"\@b的补集:@cb\n";