Time Complexity
Avg: O(1)
Worst: O(n)
A Hash Table maps keys to values using a hash function. It provides near-constant time O(1) for insert, lookup, and delete operations.
How it works:
1. A hash function converts the key into an array index
2. The value is stored at that index (bucket)
3. If two keys hash to the same index → collision
Collision handling (chaining):
Each bucket stores a list of entries.
Multiple keys can share the same bucket.
Time Complexity:
Average: O(1) for set, get, delete
Worst: O(n) when all keys collide
Space Complexity: O(n)
Applications: caches, databases, symbol tables, counting frequencies, deduplication
Related algorithms
Frequently asked questions
- What is Hash Table?
- A Hash Table maps keys to values using a hash function. It provides near-constant time O(1) for insert, lookup, and delete operations.
- What is the complexity of Hash Table?
- Time (average): O(1) for set, get, delete · Space: O(n)
- Who is this Hash Table visualizer for?
- The Hash Table visualization targets intermediate-level learners in the Data Structures category. Useful for students, interview prep, and hands-on review.
- What algorithms are related to Hash Table?
- In the same category (Data Structures) you can explore: Stack, Queue, Linked List. Each has an interactive visualization.