按元素频率顺序迭代Multiset的最简单方法是什么? [英] Simplest way to iterate through a Multiset in the order of element frequency?
问题描述
考虑这个打印出一些设备类型统计数据的例子。 (DeviceType是具有十二个值的枚举。)
Consider this example which prints out some device type stats. ("DeviceType" is an enum with a dozenish values.)
Multiset<DeviceType> histogram = getDeviceStats();
for (DeviceType type : histogram.elementSet()) {
System.out.println(type + ": " + histogram.count(type));
}
打印不同元素的最简单,最优雅的方法是什么?频率的顺序(最常见的类型是第一个)?
What's the simplest, most elegant way to print the distinct elements in the order of their frequency (most common type first)?
快速查看 Multiset
界面,没有现成的方法,也没有Guava的 Multiset
实现( HashMultiset
, TreeMultiset
等)似乎自动保留频率排序的元素。
With a quick look at the Multiset
interface, there's no ready-made method for this, and none of Guava's Multiset
implementations (HashMultiset
, TreeMultiset
, etc) seem to automatically keep elements frequency-ordered either.
推荐答案
我刚刚将此功能添加到Guava,请参阅 here 用于Javadoc。
I just added this feature to Guava, see here for the Javadoc.
编辑:的使用示例Multisets.copyHighestCountFirst()
根据原始问题:
Multiset<DeviceType> histogram = getDeviceStats();
for (DeviceType type : Multisets.copyHighestCountFirst(histogram).elementSet()) {
System.out.println(type + ": " + histogram.count(type));
}
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