company prep
Oracle
Problems frequently reported at Oracle, in course order. Solve the must-dos first.
3 easy17 medium2 hardFrequency counting ×4BST property ×3Greedy with a heap ×3Simulation ×2Tree BFS (level order) ×2Tree DFS (top-down) ×2
10 · Arrays & Strings
- #242Valid AnagramEasymust-do
- #49Group AnagramsMediummust-do
11 · Matrices & Simulation
- #54Spiral MatrixMediummust-do
15 · Linked Lists
- #206Reverse Linked ListEasymust-do
- #146LRU CacheMediummust-do
16 · Stacks & Monotonic Stack
- #155Min StackMediummust-do
- #735Asteroid CollisionMediummust-do
17 · Queues & Deques
- #239Sliding Window MaximumHardmust-do
21 · Tree Traversals
- #102Binary Tree Level Order TraversalMediummust-do
- #199Binary Tree Right Side ViewMediummust-do
22 · Tree Recursion
- #543Diameter of Binary TreeEasymust-do
23 · Binary Search Trees
- #450Delete Node in a BSTMediummust-do
- #98Validate Binary Search TreeMediummust-do
- #230Kth Smallest Element in a BSTMediummust-do
- #729My Calendar IMedium
24 · Heaps & Priority Queues
- #347Top K Frequent ElementsMediummust-do
- #621Task SchedulerMedium
- #23Merge k Sorted ListsHardmust-do
- #767Reorganize StringMedium
25 · Tries
- #208Implement Trie (Prefix Tree)Mediummust-do
- #1268Search Suggestions SystemMediummust-do
33 · Intervals
- #253Meeting Rooms IIMediummust-do