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Problem breakdowns, interview strategy, and what we learn shipping AI products.

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AlgoCracked

An AI product company in Nairobi, Kenya. We build and run AI products, and the interview-prep platform you are on.

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Challenge Library

Master algorithms and data structures with a curated collection of technical interview challenges. Filter by difficulty, topic, company, and pattern.

STATUS

DIFFICULTY

COMPANIES

All categories
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0/ 145Solved
Easy
0/25
Medium
0/99
Hard
0/21
Filters

STATUS

DIFFICULTY

COMPANIES

All categories
All tags
All patterns

145 problems

  • LFU Cache43%Hard
  • Design In-Memory File System47%Hard
  • Basic Calculator43%Hard
  • Largest Rectangle in Histogram44%Hard
  • Car Fleet52%Medium
  • Daily Temperatures67%Medium
  • Generate Parentheses73%Medium
  • Evaluate Reverse Polish Notation47%Medium
  • Min Stack53%Medium
  • Valid Parentheses41%Easy
  • Count Primes33%Medium
  • Fraction to Recurring Decimal25%Medium
  • Sqrt(x)37%Easy
  • Pow(x, n)34%Medium
  • Minimum Size Subarray Sum45%Medium
  • Range Sum Query - Immutable60%Easy
  • First Missing Positive38%Hard
  • Next Permutation39%Medium
  • Set Matrix Zeroes54%Medium
  • Rotate Image72%Medium
  • Spiral Matrix47%Medium
  • Minimum Number of Arrows to Burst Balloons57%Medium
  • Non-overlapping Intervals49%Medium
  • Merge Intervals46%Medium
  • Insert Interval38%Medium
  • Meeting Rooms II51%Medium
  • Meeting Rooms57%Easy
  • Sliding Window Maximum47%Hard
  • Best Time to Buy and Sell Stock54%Easy
  • Trapping Rain Water60%Hard
  • Container With Most Water54%Medium
  • 3Sum33%Medium
  • Longest Consecutive Sequence47%Medium
  • Valid Sudoku59%Medium
  • Product of Array Except Self65%Medium
  • Top K Frequent Elements65%Medium
  • Two Sum51%Easy
  • Contains Duplicate61%Easy
  • Android Unlock Patterns51%Medium
  • Strobogrammatic Number II50%Medium
  • N-Queens68%Hard
  • Letter Combinations of a Phone Number58%Medium
  • Palindrome Partitioning67%Medium
  • Word Search41%Medium
  • Combination Sum II54%Medium
  • Subsets II56%Medium
  • Permutations76%Medium
  • Combination Sum69%Medium
  • Subsets76%Medium
  • Alien Dictionary35%Hard
  • Word Ladder38%Hard
  • Redundant Connection63%Medium
  • Number of Connected Components in an Undirected Graph63%Medium
  • Graph Valid Tree45%Medium
  • Course Schedule II49%Medium
  • Course Schedule46%Medium
  • Surrounded Regions37%Medium
  • Pacific Atlantic Water Flow52%Medium
  • Rotting Oranges53%Medium
  • Walls and Gates60%Medium
  • Clone Graph54%Medium
  • Max Area of Island71%Medium
  • Number of Islands58%Medium
  • Find All Anagrams in a String49%Medium
  • Count and Say53%Medium
  • Reverse Words in a String42%Medium
  • Reverse String77%Easy
  • String to Integer (atoi)17%Medium
  • Longest Common Prefix42%Easy
  • Encode and Decode Strings40%Medium
  • Minimum Window Substring42%Hard
  • Permutation in String45%Medium
  • Longest Repeating Character Replacement53%Medium
  • Longest Substring Without Repeating Characters34%Medium
  • Valid Palindrome45%Easy
  • Group Anagrams67%Medium
  • Valid Anagram63%Easy
  • Jump Game38%Medium
  • Maximum Subarray50%Medium
  • Regular Expression Matching28%Hard
  • Burst Balloons58%Hard
  • Distinct Subsequences45%Hard
  • Edit Distance55%Medium
  • Interleaving String38%Medium
  • Target Sum47%Medium
  • Coin Change II62%Medium
  • Best Time to Buy and Sell Stock with Cooldown57%Medium
  • Longest Common Subsequence57%Medium
  • Minimum Path Sum64%Medium
  • Unique Paths64%Medium
  • Partition Equal Subset Sum46%Medium
  • Longest Increasing Subsequence54%Medium
  • Word Break46%Medium
  • Maximum Product Subarray35%Medium
  • Coin Change43%Medium
  • Decode Ways34%Medium
  • Palindromic Substrings69%Medium
  • Longest Palindromic Substring34%Medium
  • House Robber II41%Medium
  • House Robber50%Medium
  • Min Cost Climbing Stairs64%Easy
  • Climbing Stairs52%Easy
  • Find Median from Data Stream51%Hard
  • Design Twitter36%Medium
  • Task Scheduler57%Medium
  • Kth Largest Element in an Array67%Medium
  • K Closest Points to Origin66%Medium
  • Last Stone Weight64%Easy
  • Kth Largest Element in a Stream55%Easy
  • Word Search II38%Hard
  • Design Add and Search Words Data Structure44%Medium
  • Implement Trie (Prefix Tree)64%Medium
  • Serialize and Deserialize Binary Tree55%Hard
  • Binary Tree Maximum Path Sum39%Hard
  • Construct Binary Tree from Preorder and Inorder Traversal62%Medium
  • Kth Smallest Element in a BST70%Medium
  • Validate Binary Search Tree32%Medium
  • Count Good Nodes in Binary Tree73%Medium
  • Binary Tree Right Side View62%Medium
  • Binary Tree Level Order Traversal66%Medium
  • Lowest Common Ancestor of a Binary Search Tree65%Medium
  • Subtree of Another Tree47%Easy
  • Same Tree58%Easy
  • Balanced Binary Tree49%Easy
  • Diameter of Binary Tree58%Easy
  • Maximum Depth of Binary Tree74%Easy
  • Invert Binary Tree76%Easy
  • Reverse Nodes in k-Group56%Hard
  • Merge k Sorted Lists52%Hard
  • LRU Cache42%Medium
  • Find the Duplicate Number59%Medium
  • Linked List Cycle50%Easy
  • Add Two Numbers42%Medium
  • Copy List with Random Pointer57%Medium
  • Remove Nth Node From End of List43%Medium
  • Reorder List58%Medium
  • Merge Two Sorted Lists62%Easy
  • Reverse Linked List74%Easy
  • Median of Two Sorted Arrays37%Hard
  • Time Based Key-Value Store53%Medium
  • Search in Rotated Sorted Array39%Medium
  • Find Minimum in Rotated Sorted Array49%Medium
  • Koko Eating Bananas52%Medium
  • Search a 2D Matrix48%Medium
  • Binary Search57%Easy