Question

我的输入是n个字符串。我想获得唯一值，以及这些字符串不区分大小写的出现次数。

我想到了在数组中获取输入;对它进行排序并进行循环来计算出现率。还有其他方法吗？

Answer 1

您可以使用Stream api工具获得您想要的内容：

List<String> list = Arrays.asList("hello","world","Hola","Mundo","hello", "world","Hola","Mundo","mundo","Hello","Hola","mundo","Mundo");

Map<String, Long> ocurrences = list
        .stream()
        .map(String::toLowerCase) // make case insensitive
        .collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));

System.out.println(ocurrences);

输出：

{world = 2，mundo = 5，hello = 3，hola = 3}

Answer 2

public Map<String, Integer> calculateOccurences(Collection<String> collectionOfStrings) {
        HashMap<String, Integer> map = new HashMap<String, Integer>();
        for (String string : collectionOfStrings) {
            String stringAsLowerCase = string.toLowerCase();
            Integer integer = map.get(stringAsLowerCase);
            if (integer == null) { //this has never been added
                map.put(stringAsLowerCase, 1);
            } else {
                map.put(stringAsLowerCase, integer + 1);
            }
        }
        return map;
    }

这将返回一个地图，其中的键是唯一的单词，每个值都会告诉你它出现了多少次。

Java String Array最小唯一出现次数

2 个答案: