#705

Design HashSet

pupil · 310 · lc easy +21 · 67.8% accepted · 4,031 likes · top 74%

Description

Build a HashSet from scratch without relying on any built-in hash table libraries.

Implement the MyHashSet class:

- void add(key) Adds key to the set.

- bool contains(key) Returns true if key is in the set, otherwise false.

- void remove(key) Removes key from the set; does nothing if key is absent.

Example 1:

Input

["MyHashSet", "add", "add", "contains", "contains", "add", "contains", "remove", "contains"]

[[], [1], [2], [1], [3], [2], [2], [2], [2]]

Output

[null, null, null, true, false, null, true, null, false]

Example 2:

Explanation

MyHashSet myHashSet = new MyHashSet();

myHashSet.add(1); // set = [1]

myHashSet.add(2); // set = [1, 2]

myHashSet.contains(1); // return True

myHashSet.contains(3); // return False, (not found)

myHashSet.add(2); // set = [1, 2]

myHashSet.contains(2); // return True

myHashSet.remove(2); // set = [1]

myHashSet.contains(2); // return False, (already removed)

Code

class MyHashSet:

    def __init__(self):
        

    def add(self, key: int) -> None:
        

    def remove(self, key: int) -> None:
        

    def contains(self, key: int) -> bool:
        


# Your MyHashSet object will be instantiated and called as such:
# obj = MyHashSet()
# obj.add(key)
# obj.remove(key)
# param_3 = obj.contains(key)

class MyHashSet:

    def __init__(self):
        

    def add(self, key: int) -> None:
        

    def remove(self, key: int) -> None:
        

    def contains(self, key: int) -> bool:
        


# Your MyHashSet object will be instantiated and called as such:
# obj = MyHashSet()
# obj.add(key)
# obj.remove(key)
# param_3 = obj.contains(key)