Data Structures & AlgorithmsEasy
Sliding Window Pattern — Algorithm with Visual Step-by-Step
Arrays store elements in contiguous memory locations, allowing O(1) access by index. They're the most fundamental data structure and the building block for many others. Understanding when arrays excel and when they struggle is crucial for algorithm design.
1 concepts·6 practice problems·Beginner level
Key Concepts
- •Elements stored in contiguous (sequential) memory
- •O(1) access by index - direct memory address calculation
- •O(n) search in unsorted array - must check each element
- •O(n) insert/delete in middle - must shift elements
- •Fixed size in most languages (JS arrays are dynamic)
- •Great cache performance due to memory locality
Practice Problems
Common Mistakes to Avoid
- ×Using array.shift() in a loop (O(n²) total)
- ×Not considering that splice is O(n)
- ×Assuming JS arrays work like other languages (they're actually objects)
- ×Using arrays when a hash map would give O(1) lookup
Interview Tips
- ✓Arrays are great when you need index-based access
- ✓For frequent front operations, consider a deque or linked list
- ✓Sorted arrays enable O(log n) binary search
- ✓Two-pointer techniques often work well on sorted arrays