假设我们有以下两个数组
String[] keys = new String[] {"a", "b", "c", "aa", "d", "b"}
int[] values = new int[] { 1 , 2 , 3 , 4 , 5 , 6 }
通过将这两个数组合并到 HashTable 中,我们得到以下结果
// pseudo-code
Map<String, Integer> dictionary = new HashTable<>(
("a" => 1)
("b" => 8) // because "b" appeared in index 1 and 5
("c" => 3)
("aa" => 4)
("d" => 5)
);
我们如何使用 java Lambda 风格来做到这一点?
到目前为止我有以下内容:
// this loops through the range given (used for index start and end)
// and sums the values of duplicated keys
tree.listMap = IntStream.range(range[0], range[1]).boxed().collect(
Collectors.toMap(i - > dictionary[i], i - > i + 1, Integer::sum, TreeMap::new)
);
但是,我想采用 2 个数组,按键和值合并它们,其中值是重复键的所有值的总和。我们应该怎么做?