Oracle coding interview questions

77 DSA problems tagged as asked at Oracle, with statements, examples and constraints — practise free on CampusCode.

13. Find All Duplicates in Array Easy Array
58. Lucky Number in a Matrix Easy Array
67. Spiral Matrix Traversal Medium Array
72. Sort Colors (Dutch National Flag) Medium Array
77. Search in Rotated Sorted Array Medium Array
97. Count Number of Nice Subarrays Medium Array
98. Longest Mountain in Array Medium Array
106. Subarray Product Less Than K Medium Array
111. First Missing Positive Hard Array
113. Sliding Window Maximum Hard Array
133. Create Maximum Number Hard Array
168. Count and Say Easy String
190. Longest Substring Without Repeating Characters (Brute) Easy String
207. Largest Number (Array to String Sort) Easy String
208. Decode String (Nested Brackets — Easy Variant) Easy String
210. Longest Substring Without Repeating Characters Medium String
212. Group Anagrams Medium String
216. ZigZag Conversion Medium String
217. Multiply Strings Medium String
222. Restore IP Addresses (Count) Medium String
227. Reorganize String (Feasibility) Medium String
229. Permutation in String Medium String
232. Simplify Path Medium String
234. Decode String Medium String
246. Reverse Vowels of a String Medium String
247. Largest Number Medium String
250. Longest Substring with At Most K Distinct Characters Medium String
262. Word Break II (Count of Segmentations) Hard String
269. Word Ladder (Shortest Transformation Length) Hard String
285. Integer to English Words Hard String
297. Reverse a Linked List Easy Linked List
358. Add Two Numbers II (No Reverse Allowed) Medium Linked List
384. Convert Binary Number in Linked List to Integer Medium Linked List
386. Swapping Nodes in a Linked List (Values) Medium Linked List
393. Remove Duplicates from Sorted List II Medium Linked List
394. Merge K Sorted Lists (Optimal — Min Heap) Hard Linked List
438. Find in Mountain Array (Bitonic Search) Easy Binary Search
474. Search a 2D Matrix II (Row & Column Sorted) Easy Binary Search
478. Search in Rotated Sorted Array (With Duplicates) Medium Binary Search
484. Find the Smallest Divisor Given a Threshold Medium Binary Search
498. Maximum Candies Allocated to K Children Medium Binary Search
521. Maximum Number of Events That Can Be Attended Medium Binary Search
524. Search a 2D Matrix Medium Binary Search
527. Kth Smallest Element in a Sorted Matrix Hard Binary Search
530. Find in Mountain Array Hard Binary Search
556. Maximum Profit in Job Scheduling (Binary Search + DP) Hard Binary Search
576. Remove All Adjacent Duplicates in String Easy Stack
584. Sliding Window Maximum Easy Stack
612. Decode String (Nested Brackets) Medium Stack
613. Asteroid Collision Medium Stack
621. Sliding Window Maximum (Monotonic Deque) Medium Stack
622. Task Scheduler (Greedy + Queue) Medium Stack
628. Open the Lock (BFS + Queue) Medium Stack
631. Number of Visible People in Queue Medium Stack
657. Basic Calculator III Hard Stack
659. Remove Invalid Parentheses Hard Stack
685. Bus Routes Hard Stack
686. Flatten Binary Tree to Linked List Hard Stack
754. Combination Sum II (Each Element Used Once) Medium Recursion
766. Flood Fill Algorithm Medium Recursion
848. Diameter of Binary Tree Easy Trees
885. Kth Smallest Element in BST Easy Trees
898. Flatten Binary Tree to Linked List Medium Trees
899. Populating Next Right Pointers in Each Node Medium Trees
900. Binary Tree Right Side View Medium Trees
901. Sum Root to Leaf Numbers Medium Trees
905. All Nodes Distance K in Binary Tree Medium Trees
957. Kth Smallest Element in a Sorted Matrix Hard Trees
989. Number of Islands (DFS) Easy Graphs
991. Max Area of Island Easy Graphs
999. Island Perimeter Easy Graphs
1000. Number of Closed Islands Easy Graphs
1023. Redundant Connection Easy Graphs
1061. Keys and Rooms Medium Graphs
1185. Largest Divisible Subset Medium Dynamic Programming
1200. Diameter of Binary Tree (DP) Medium Dynamic Programming
1208. Maximum Profit in Job Scheduling Medium Dynamic Programming