Java DSA Cheat Sheets & Interview Study Notes
Free concise Data Structures and Algorithms study notes, time complexity cheat sheets, and Java coding interview pattern references. Ideal for last-minute revision before technical interviews.
DSA Time Complexity Cheat Sheet
- Array access: O(1) | Array search: O(n) | Array insert: O(n)
- HashMap get/put: O(1) average | HashSet lookup: O(1)
- Binary Search: O(log n) | Merge Sort: O(n log n) | Quick Sort: O(n log n) average
- BFS/DFS on graph: O(V + E) | Dijkstra: O((V + E) log V)
- Dynamic Programming (memoization): O(n * m) for 2D problems
Key Java DSA Collections
- ArrayList, LinkedList, ArrayDeque, PriorityQueue (min/max heap)
- HashMap, LinkedHashMap, TreeMap (sorted), HashSet, TreeSet
- Stack via Deque, Queue via LinkedList or ArrayDeque
All notes are free on CupOfDsa. Pair your study with our free DSA practice problems and algorithmic pattern guides.