Two Sum III - Data structure design

lcpy gen -n 170   # by problem number
lcpy gen -s two_sum_iii_data_structure_design   # by problem name

Input
["TwoSum", "add", "add", "add", "find", "find"]
[[], [1], [3], [5], [4], [7]]
Output
[null, null, null, null, true, false]

Explanation
TwoSum twoSum = new TwoSum();
twoSum.add(1);
twoSum.add(3);
twoSum.add(5);
twoSum.find(4); // 1 + 3 = 4, return true
twoSum.find(7); // No two integers sum up to 7, return false

from collections import defaultdict


class TwoSum:
    def __init__(self) -> None:
        self.cnt: defaultdict[int, int] = defaultdict(int)

    def add(self, number: int) -> None:
        self.cnt[number] += 1

    def find(self, value: int) -> bool:
        for x, v in self.cnt.items():
            y = value - x
            if y in self.cnt and (x != y or v > 1):
                return True
        return False