Design a HashSet without using any built-in hash table libraries.
Implement MyHashSet class:
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]
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)
์ ํ์ฌํญ
- 0 โค key โค
- At most 104 calls will be made to add, remove, and contains.
class MyHashSet:
def __init__(self):
self.hs = set()
def add(self, key: int) -> None:
self.hs.add(key)
def remove(self, key: int) -> None:
self.hs.discard(key)
def contains(self, key: int) -> bool:
return key in self.hs
์๊ฐ๋ณต์ก๋ O(1)
class MyHashSet:
def __init__(self):
self.hs = []
def add(self, key: int) -> None:
if not self.contains(key):
self.hs.append(key)
def remove(self, key: int) -> None:
if self.contains(key):
self.hs.remove(key)
def contains(self, key: int) -> bool:
return key in self.hs
์๊ฐ๋ณต์ก๋ O(n)
class MyHashSet:
BUCKET_SIZE = 256
def __init__(self):
self.hs = [[] for _ in range(self.BUCKET_SIZE)]
def add(self, key: int) -> None:
if not self.contains(key):
self.curr.append(key)
def remove(self, key: int) -> None:
if self.contains(key):
self.curr.remove(key)
def contains(self, key: int) -> bool:
self.curr = self.hs[key%self.BUCKET_SIZE]
return key in self.curr
์๊ฐ๋ณต์ก๋ O(BUCKET_SIZE)