Design Hash Set

LeetCode Problem

# http://leetcode.com/problems/design-hashset/description/
class ListNode:
    def __init__(self, key):
        self.key = key
        self.next = None


class MyHashSet:
    def __init__(self):
        self.set = [ListNode(0) for i in range(10**4)]  # dummy node

    def add(self, key: int) -> None:
        # index = key % len(self.set)
        cur = self.set[key % len(self.set)]
        while cur.next:
            # duplicate
            if cur.next.key == key:
                return
            cur = cur.next
        # go to end
        cur.next = ListNode(key)

    def remove(self, key: int) -> None:
        cur = self.set[key % len(self.set)]
        while cur.next:
            # duplicate
            if cur.next.key == key:
                cur.next = cur.next.next
                return
            cur = cur.next

    def contains(self, key: int) -> bool:
        cur = self.set[key % len(self.set)]
        while cur.next:
            # duplicate
            if cur.next.key == key:
                return True
            cur = cur.next
        return False