Practice Design HashSet

Read the task, work through the examples, and check your approach against the constraints. Use the original LeetCode task for coding and submissions.

Easy#705

LeetCode Problem

Design HashSet

Array Hash Table Linked List Design Hash Function

Problem Statement

Implement MyHashSet without using a built-in hash-table library. add(key) makes the key present; adding an existing key has no additional effect. contains(key) reports presence. remove(key) makes the key absent and does nothing if it was already absent. Practice approach: Use a boolean direct-address array for the stated key range, or implement buckets and collision handling. Repeated insertions must not create duplicates that survive one removal. Test repeated insertion, absent-key removal, and both endpoint keys.

Source: Design HashSet on LeetCode. Use the original task for its coding environment and submissions.

Examples

# Example 1

Input

["MyHashSet","add","add","contains","remove","contains","remove"]
[[],[6],[6],[6],[6],[6],[6]]

Output

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

Explanation

Adding 6 twice leaves one set entry; one removal makes contains(6) false.

Constraints

0 <= key <= 10^6

At most 10^4 total calls to add, remove, and contains.

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