Design HashSet - Leetcode 705 - Python

Solving Leetcode 705 - Design hashset, today's daily leetcode on may 29.

0:00 - Read the problem
1:25 - Drawing Explanation
6:35 - Coding Explanation

leetcode 705

#neetcode #leetcode #python

[metarus]

Where have you gone neetcode? you dont post new videos anymore and you also dont upload more content for ppl like me who paid for Pro.

[MP-nyep]

Thank you for the daily leetcode problems!

[redniq]

That's not a bug . It's a feature. It uses a reference to the pointer of ListNode(0).

when you print(ListNode(0)). it will print the address in memory.

[siddharthtanwar]

why create a dummy node? why not fill values from the first node itself?

[MansoorLunawadi]

Hello, I am following this solution word by word on LeetCode but it is saying time limit exceeded

[lingyuhu]

is it worth solving with binary search tree?

[servantofthelord]

Could we use a deque instead of a custom ListNode class? :

from collections import deque
class MyHashSet:

def __init__(self):
self.num_buckets = 10000
self.elements = [deque() for i in range(self.num_buckets)]


def add(self, key: int) -> None:
if not self.contains(key):
bucket = key % self.num_buckets


def remove(self, key: int) -> None:
if self.contains(key):
bucket = key % self.num_buckets



def contains(self, key: int) -> bool:
bucket = key % self.num_buckets
for node in self.elements[bucket]:
if node == key:
return True
return False

[madhuvamsimachavarapu]

7:20 AWESOME!! That was my bug and I didnt know Python does that :P Thank U

[michaelyao]

Can we just use a two-demension array for python solution?

[memeproductions]

why use a linked list over a simple array for collisions, operations are still going to be O(n) with n the number of collisions, aren't they?

[thegreatestcomesfromthewor]

Thank you for the video!! I thought there should be a linked list class in case of duplicate values but there is just node class. Could you explain this plz?

[flatmapper]

It's ok to have collisions. There is a balance between number of collisions, number of operations and performance

[vietnguyenquoc]

Another way to achieve the constant O(1) time for contains() method is using boolean array with index acts as key, but the memory suffer though (constrain is 0 <= key <= 10^6)

[medam]

what if key == 0 ? you will create another Node with a value of 0 ?

[TheElementFive]

Can you do 1206 design skip list, next? :)