Apple Interview Questions — 100 DSA Problems

100 problems with full solutions in Python, Java, C++, JavaScript, Go, Rust.

Most frequently asked Apple LeetCode questions for software engineering interviews.

• Two Sum (EASY) — Array, Hash Table
• Longest Substring Without Repeating Characters (MEDIUM) — Hash Table, String, Sliding Window
• Longest Common Prefix (EASY) — String, Trie
• Valid Parentheses (EASY) — String, Stack
• Median of Two Sorted Arrays (HARD) — Array, Binary Search, Divide and Conquer
• Merge Intervals (MEDIUM) — Array, Sorting
• Group Anagrams (MEDIUM) — Array, Hash Table, String, Sorting
• Merge Sorted Array (EASY) — Array, Two Pointers, Sorting
• Trapping Rain Water (HARD) — Array, Two Pointers, Dynamic Programming, Stack, Monotonic Stack
• Reverse Integer (MEDIUM) — Math
• Valid Sudoku (MEDIUM) — Array, Hash Table, Matrix
• Climbing Stairs (EASY) — Math, Dynamic Programming, Memoization
• Longest Palindromic Substring (MEDIUM) — Two Pointers, String, Dynamic Programming
• Palindrome Number (EASY) — Math
• Rotate Image (MEDIUM) — Array, Math, Matrix
• Spiral Matrix (MEDIUM) — Array, Matrix, Simulation
• Add Two Numbers (MEDIUM) — Linked List, Math, Recursion
• 3Sum (MEDIUM) — Array, Two Pointers, Sorting
• Roman to Integer (EASY) — Hash Table, Math, String
• Remove Duplicates from Sorted Array (EASY) — Array, Two Pointers
• Search in Rotated Sorted Array (MEDIUM) — Array, Binary Search
• Sqrt(x) (EASY) — Math, Binary Search
• Maximum Subarray (MEDIUM) — Array, Divide and Conquer, Dynamic Programming
• Merge Two Sorted Lists (EASY) — Linked List, Recursion
• Generate Parentheses (MEDIUM) — String, Dynamic Programming, Backtracking
• Merge k Sorted Lists (HARD) — Linked List, Divide and Conquer, Heap (Priority Queue), Merge Sort
• Container With Most Water (MEDIUM) — Array, Two Pointers, Greedy
• Find the Index of the First Occurrence in a String (EASY) — Two Pointers, String, String Matching
• Remove Element (EASY) — Array, Two Pointers
• Search Insert Position (EASY) — Array, Binary Search
• Letter Combinations of a Phone Number (MEDIUM) — Hash Table, String, Backtracking
• Regular Expression Matching (HARD) — String, Dynamic Programming, Recursion
• Remove Nth Node From End of List (MEDIUM) — Linked List, Two Pointers
• Insert Interval (MEDIUM) — Array
• Largest Rectangle in Histogram (HARD) — Array, Stack, Monotonic Stack
• Add Binary (EASY) — Math, String, Bit Manipulation, Simulation
• Permutations (MEDIUM) — Array, Backtracking
• Maximum Depth of Binary Tree (EASY) — Tree, Depth-First Search, Breadth-First Search, Binary Tree
• Binary Tree Level Order Traversal (MEDIUM) — Tree, Breadth-First Search, Binary Tree
• Find First and Last Position of Element in Sorted Array (MEDIUM) — Array, Binary Search
• Next Permutation (MEDIUM) — Array, Two Pointers
• Combination Sum (MEDIUM) — Array, Backtracking
• Sort Colors (MEDIUM) — Array, Two Pointers, Sorting
• Jump Game (MEDIUM) — Array, Dynamic Programming, Greedy
• 4Sum (MEDIUM) — Array, Two Pointers, Sorting
• Symmetric Tree (EASY) — Tree, Depth-First Search, Breadth-First Search, Binary Tree
• String to Integer (atoi) (MEDIUM) — String
• Validate Binary Search Tree (MEDIUM) — Tree, Depth-First Search, Binary Search Tree, Binary Tree
• First Missing Positive (HARD) — Array, Hash Table
• Pow(x, n) (MEDIUM) — Math, Recursion