Oracle Interview Questions (340)

Practice real interview problems from Oracle

Title	Solution	Practice	Difficulty	Companies	Topics
1. Two Sum	Solution	Solve	Easy	Accenture+128	Array Hash Table
9. Palindrome Number	Solution	Solve	Easy	Accenture+34	Math
13. Roman to Integer	Solution	Solve	Easy	Accenture+44	Hash Table Math+1
14. Longest Common Prefix	Solution	Solve	Easy	Accenture+56	String Trie
20. Valid Parentheses	Solution	Solve	Easy	Accenture+118	Stack String
21. Merge Two Sorted Lists	Solution	Solve	Easy	Adobe+39	Linked List Recursion
26. Remove Duplicates from Sorted Array	Solution	Solve	Easy	Accenture+27	Array Two Pointers
69. Sqrt(x)	Solution	Solve	Easy	Adobe+18	Binary Search Math
70. Climbing Stairs	Solution	Solve	Easy	Accenture+37	Dynamic Programming Math+1
83. Remove Duplicates from Sorted List	Solution	Solve	Easy	Adobe+9	Linked List
88. Merge Sorted Array	Solution	Solve	Easy	Accenture+41	Array Sorting+1
104. Maximum Depth of Binary Tree	Solution	Solve	Easy	Accenture+15	Binary Tree Breadth-First Search+2
121. Best Time to Buy and Sell Stock	Solution	Solve	Easy	Accenture+103	Array Dynamic Programming
125. Valid Palindrome	Solution	Solve	Easy	Accenture+41	String Two Pointers
141. Linked List Cycle	Solution	Solve	Easy	Accenture+24	Hash Table Linked List+1
169. Majority Element	Solution	Solve	Easy	Accenture+21	Array Counting+3
202. Happy Number	Solution	Solve	Easy	Accenture+30	Hash Table Math+1
203. Remove Linked List Elements	Solution	Solve	Easy	Amazon+8	Linked List Recursion
205. Isomorphic Strings	Solution	Solve	Easy	Accenture+20	Hash Table String
206. Reverse Linked List	Solution	Solve	Easy	Accenture+35	Linked List Recursion
217. Contains Duplicate	Solution	Solve	Easy	Accenture+22	Array Hash Table+1
226. Invert Binary Tree	Solution	Solve	Easy	Amazon+10	Binary Tree Breadth-First Search+2
234. Palindrome Linked List	Solution	Solve	Easy	Adobe+17	Linked List Recursion+2
242. Valid Anagram	Solution	Solve	Easy	Accenture+40	Hash Table Sorting+1
252. Meeting Rooms	Solution	Solve	Easy	Amazon+9	Array Sorting
268. Missing Number	Solution	Solve	Easy	Adobe+20	Array Binary Search+4
270. Closest Binary Search Tree Value	Solution	Solve	Easy	Amazon+8	Binary Search Binary Search Tree+3
283. Move Zeroes	Solution	Solve	Easy	Accenture+48	Array Two Pointers
338. Counting Bits	Solution	Solve	Easy	Adobe+8	Bit Manipulation Dynamic Programming
345. Reverse Vowels of a String	Solution	Solve	Easy	Accenture+11	String Two Pointers
359. Logger Rate Limiter	Solution	Solve	Easy	Amazon+18	Data Stream Design+1
387. First Unique Character in a String	Solution	Solve	Easy	Accenture+24	Counting Hash Table+2
409. Longest Palindrome	Solution	Solve	Easy	Accenture+7	Greedy Hash Table+1
412. Fizz Buzz	Solution	Solve	Easy	Agoda+18	Math Simulation+1
415. Add Strings	Solution	Solve	Easy	Airbnb+14	Math Simulation+1
448. Find All Numbers Disappeared in an Array	Solution	Solve	Easy	Adobe+8	Array Hash Table
463. Island Perimeter	Solution	Solve	Easy	Amazon+9	Array Breadth-First Search+2
496. Next Greater Element I	Solution	Solve	Easy	Accenture+16	Array Hash Table+2
543. Diameter of Binary Tree	Solution	Solve	Easy	Adobe+18	Binary Tree Depth-First Search+1
605. Can Place Flowers	Solution	Solve	Easy	Airbnb+15	Array Greedy
653. Two Sum IV - Input is a BST	Solution	Solve	Easy	Amazon+8	Binary Search Tree Binary Tree+5
696. Count Binary Substrings	Solution	Solve	Easy	Adobe+19	String Two Pointers
697. Degree of an Array	Solution	Solve	Easy	Amazon+12	Array Hash Table
700. Search in a Binary Search Tree	Solution	Solve	Easy	Adobe+7	Binary Search Tree Binary Tree+1
704. Binary Search	Solution	Solve	Easy	Adobe+12	Array Binary Search
706. Design HashMap	Solution	Solve	Easy	Amazon+14	Array Design+3
796. Rotate String	Solution	Solve	Easy	Accenture+12	String String Matching
844. Backspace String Compare	Solution	Solve	Easy	Agoda+14	Simulation Stack+2
872. Leaf-Similar Trees	Solution	Solve	Easy	Amazon+5	Binary Tree Depth-First Search+1
1002. Find Common Characters	Solution	Solve	Easy	Amazon+7	Array Hash Table+1