Apple Coding Interview Questions

Solid fundamentals across trees, recursion, and low-level clarity.

#	Title	Difficulty	Topics
1	Two Sum	Easy	hash table
7	Reverse Integer	Easy	math
21	Merge Two Sorted Lists	Easy	linked list
36	Valid Sudoku	Easy	hash table
42	Trapping Rain Water	Hard	greedy
48	Rotate Image	Medium	array
53	Maximum Subarray	Easy	dynamic programming
69	Sqrt(x)	Medium	binary search
70	Climbing Stairs	Easy	dynamic programming
98	Validate Binary Search Tree	Medium	recursion
100	Same Tree	Easy	recursion
104	Maximum Depth of Binary Tree	Easy	recursion
108	Convert Sorted Array to Binary Search Tree	Medium	recursion
118	Pascal's Triangle	Easy	array
119	Pascal's Triangle II	Easy	array
141	Linked List Cycle	Easy	two pointers
149	Max Points on a Line	Hard	hash table
151	Reverse Words in a String	Medium	string
165	Compare Version Numbers	Easy	string
167	Two Sum II - Input array is sorted	Medium	two pointers
179	Largest Number	Medium	sort
190	Reverse Bits	Easy	bit manipulation
191	Number of 1 Bits	Easy	bit manipulation
198	House Robber	Easy	dynamic programming
200	Number of Islands	Medium	depth first search
202	Happy Number	Easy	hash table
206	Reverse Linked List	Easy	linked list
215	Kth Largest Element in an Array	Medium	array
217	Contains Duplicate	Easy	hash table
221	Maximal Square	Medium	dynamic programming
234	Palindrome Linked List	Easy	linked list
236	Lowest Common Ancestor of a Binary Tree	Medium	depth first search
237	Delete Node in a Linked List	Easy	linked list
238	Product of Array Except Self	Medium	array
240	Search a 2D Matrix II	Medium	array
257	Binary Tree Paths	Easy	depth first search
283	Move Zeroes	Easy	two pointers
344	Reverse String	Easy	two pointers
383	Ransom Note	Easy	string