Apple

The 40 Apple interview problems asked most — recent (last six months) first, then all-time frequency — grouped by pattern.

0 / 40 done

Arrays & Hashing

Two Pointers

Sliding Window

Best Time to Buy and Sell Stock↻Easy
Design Hit Counter↻Medium
Longest Substring Without Repeating Characters↻Medium
Subarray Product Less Than K↻Medium

Stack

Basic Calculator II↻Medium

Binary Search

Time Based Key Value Store↻Medium
Median of Two Sorted Arrays↻Hard
Find First and Last Position of Element in Sorted Array↻Medium
Search In Rotated Sorted Array↻Medium

Linked List

Tries

Implement Trie Prefix Tree↻Medium

Heap / Priority Queue

Find Median From Data Stream↻Hard

Backtracking

Letter Combinations of a Phone Number↻Medium

Graphs

1-D DP

Longest Palindromic Substring↻Medium

Greedy

Best Time to Buy and Sell Stock II↻Medium
Best Time to Buy and Sell Stock with Transaction Fee↻Medium

Intervals

Merge Intervals↻Medium

Math & Geometry

Spiral Matrix↻Medium
Rotate Image↻Medium

Strings

Longest Common Prefix↻Easy

Bit Manipulation

Reverse Integer↻Medium