保持元素计数并检索计数在范围内的元素的数据结构

Question

我需要一个数据结构来保留元素数，然后在一定范围内检索元素。

示例：

counter = RangeCounter()
for el in [1, 1, 2, 2, 2, 0]
    counter.add(el)

counter.get(occurence >= 1 and occurence <= 2)
>>> 1, 2 (element 1 is encountered 2 times)
>>> 2, 3 (element 2 in encountered 3 times)

Answer 1

使用collections.Counter，您可以执行所有操作：

from collections import Counter

counter = Counter([1, 1, 2, 2, 2, 0])
# Counter({2: 3, 1: 2, 0: 1})

# occurence >= 1 and occurence <= 2
res = {item: count for item, count in counter.items() if 1 <= count <= 2}
# {1: 2, 0: 1}