Hash Table
A hash table turns a key into a slot. With a decent hash and a controlled load factor, lookup does not scan the table. A bad collision chain can.
Costs
| Category | Data Structure |
| Difficulty | Medium |
| Average lookup, insert, delete | O(1) |
| Worst, one long chain | O(n) |
| Load factor | resize before chains grow |
Questions
What is Hash Table?
A hash table turns a key into a slot. With a decent hash and a controlled load factor, lookup does not scan the table. A bad collision chain can.
Where do I practice it?
DSA Master keeps challenges and progress on the phone. This page is the idea and the costs.