Data Structures & AlgorithmsEasy
Linked Lists — Data Structure Guide with JavaScript Visualizations
A linked list is a sequence of nodes where each node contains data and a pointer to the next node. Unlike arrays, linked lists don't require contiguous memory, making insertions and deletions efficient. However, they sacrifice random access.
1 concepts·6 practice problems·Beginner level
Key Concepts
- •Each node has: data + pointer to next node
- •No contiguous memory needed - nodes can be anywhere
- •O(1) insert/delete if you have the node reference
- •O(n) access - must traverse from head
- •Types: singly linked, doubly linked, circular
- •Trade-off: fast insert/delete vs slow random access
Practice Problems
Common Mistakes to Avoid
- ×Losing reference to head (always keep track!)
- ×Not handling null/empty list edge cases
- ×Creating cycles accidentally during manipulation
- ×Forgetting to update both prev and next in doubly linked
Interview Tips
- ✓Draw the pointers! Visualize before coding
- ✓Use dummy head node to simplify edge cases
- ✓Fast/slow pointer technique solves many problems
- ✓Know trade-offs vs arrays: insert O(1) vs access O(n)