消除数组的Perl散列中的单一化值

use strict;
use warnings;

# 示例散列
my %hash = (
    a => 1,
    b => 2,
    c => 1,
    d => 3,
    e => 2,
);

# 创建一个新的散列来存储出现多次的值
my %filtered_hash;

# 遍历原始散列
foreach my $key (keys %hash) {
    my $value = $hash{$key};
    # 检查值的出现次数
    if (($hash{$_} == $value) && ($key ne $_)) {
        $filtered_hash{$key} = $value;
        $filtered_hash{$_} = $value;
    }
}

# 打印结果
print "Filtered Hash:\n";
foreach my $key (keys %filtered_hash) {
    print "$key => $filtered_hash{$key}\n";
}