Bitmask LeetCode Problems: All 43, With Python Solutions
Every problem in this library that LeetCode tags Bitmask — 43 in total, 35 of them with a complete Python solution, a worked example and the time and space complexity of the approach.
- 43 problems
- 0 Easy
- 16 Medium
- 27 Hard
How Bitmask problems are solved
A tag names the subject, not the method. These pattern hubs cover the techniques that actually solve Bitmask problems — each one explains the approach, gives a Python template and states its complexity.
- Bit Manipulation — Use XOR, masks and the low-bit trick to replace whole data structures with an integer.
Bitmask problems by difficulty
Problems with a complete Python solution are listed first, then by ascending problem number.
Medium (16)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 464 | Can I Win | Medium | Bit Manipulation, Memoization, Math +3 |
| 473 | Matchsticks to Square | Medium | Bit Manipulation, Array, Dynamic Programming +2 |
| 526 | Beautiful Arrangement | Medium | Bit Manipulation, Array, Dynamic Programming +2 |
| 638 | Shopping Offers | Medium | Bit Manipulation, Memoization, Array +3 |
| 698 | Partition to K Equal Sum Subsets | Medium | Bit Manipulation, Memoization, Array +3 |
| 1947 | Maximum Compatibility Score Sum | Medium | Bit Manipulation, Array, Dynamic Programming +2 |
| 1986 | Minimum Number of Work Sessions to Finish the Tasks | Medium | Bit Manipulation, Array, Dynamic Programming +2 |
| 2002 | Maximum Product of the Length of Two Palindromic Subsequences | Medium | Bit Manipulation, String, Dynamic Programming +2 |
| 2305 | Fair Distribution of Cookies | Medium | Bit Manipulation, Array, Dynamic Programming +2 |
| 2572 | Count the Number of Square-Free Subsets | Medium | Bit Manipulation, Array, Math +2 |
| 2741 | Special Permutations | Medium | Bit Manipulation, Array, Dynamic Programming +1 |
| 351 | Android Unlock PatternsPremium | Medium | Bit Manipulation, Dynamic Programming, Backtracking +1 |
| 1066 | Campus Bikes IIPremium | Medium | Bit Manipulation, Array, Dynamic Programming +2 |
| 2152 | Minimum Number of Lines to Cover PointsPremium | Medium | Bit Manipulation, Geometry, Array +5 |
| 2184 | Number of Ways to Build Sturdy Brick WallPremium | Medium | Bit Manipulation, Array, Dynamic Programming +1 |
| 2992 | Number of Self-Divisible PermutationsPremium | Medium | Bit Manipulation, Array, Math +4 |
Hard (27)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 691 | Stickers to Spell Word | Hard | Bit Manipulation, Memoization, Array +5 |
| 805 | Split Array With Same Average | Hard | Bit Manipulation, Array, Math +2 |
| 847 | Shortest Path Visiting All Nodes | Hard | Bit Manipulation, Breadth-First Search, Graph +2 |
| 943 | Find the Shortest Superstring | Hard | Bit Manipulation, Array, String +2 |
| 996 | Number of Squareful Arrays | Hard | Bit Manipulation, Array, Hash Table +4 |
| 1125 | Smallest Sufficient Team | Hard | Bit Manipulation, Array, Dynamic Programming +1 |
| 1255 | Maximum Score Words Formed by Letters | Hard | Bit Manipulation, Array, Hash Table +5 |
| 1349 | Maximum Students Taking Exam | Hard | Bit Manipulation, Array, Dynamic Programming +2 |
| 1434 | Number of Ways to Wear Different Hats to Each Other | Hard | Bit Manipulation, Array, Dynamic Programming +1 |
| 1494 | Parallel Courses II | Hard | Bit Manipulation, Graph, Dynamic Programming +1 |
| 1595 | Minimum Cost to Connect Two Groups of Points | Hard | Bit Manipulation, Array, Dynamic Programming +2 |
| 1617 | Count Subtrees With Max Distance Between Cities | Hard | Bit Manipulation, Tree, Dynamic Programming +2 |
| 1655 | Distribute Repeating Integers | Hard | Bit Manipulation, Array, Dynamic Programming +2 |
| 1659 | Maximize Grid Happiness | Hard | Bit Manipulation, Memoization, Dynamic Programming +1 |
| 1681 | Minimum Incompatibility | Hard | Bit Manipulation, Array, Dynamic Programming +1 |
| 1723 | Find Minimum Time to Finish All Jobs | Hard | Bit Manipulation, Array, Dynamic Programming +2 |
| 1755 | Closest Subsequence Sum | Hard | Bit Manipulation, Array, Two Pointers +3 |
| 1799 | Maximize Score After N Operations | Hard | Bit Manipulation, Array, Math +4 |
| 1815 | Maximum Number of Groups Getting Fresh Donuts | Hard | Bit Manipulation, Memoization, Array +2 |
| 1879 | Minimum XOR Sum of Two Arrays | Hard | Bit Manipulation, Array, Dynamic Programming +1 |
| 1994 | The Number of Good Subsets | Hard | Bit Manipulation, Array, Hash Table +5 |
| 2035 | Partition Array Into Two Arrays to Minimize Sum Difference | Hard | Bit Manipulation, Array, Two Pointers +4 |
| 2172 | Maximum AND Sum of Array | Hard | Bit Manipulation, Array, Dynamic Programming +1 |
| 2791 | Count Paths That Can Form a Palindrome in a Tree | Hard | Bit Manipulation, Tree, Depth-First Search +2 |
| 465 | Optimal Account BalancingPremium | Hard | Bit Manipulation, Array, Dynamic Programming +2 |
| 2247 | Maximum Cost of Trip With K HighwaysPremium | Hard | Bit Manipulation, Graph, Dynamic Programming +1 |
| 2403 | Minimum Time to Kill All MonstersPremium | Hard | Bit Manipulation, Array, Dynamic Programming +1 |
Keep exploring
All LeetCode topicsEvery tag with a page of its own, with the number of problems behind each.LeetCode patternsThe techniques themselves, with a Python template and complexity for each.Curated study listsBlind 75, NeetCode 150 and three more, grouped by pattern.Easy problemsStart here when the data structure is new rather than the problem.
Other topics
- Array1,569
- String672
- Hash Table588
- Math485
- Dynamic Programming481
- Sorting392
- Greedy346
- Depth-First Search289
- Binary Search253
- Database249
- Tree225
- Breadth-First Search223
- Matrix216
- Two Pointers201
- Bit Manipulation194
- Binary Tree174
- Heap (Priority Queue)163
- Prefix Sum157
- Stack157
- Simulation144
- Graph138
- Counting126
- Design122
- Sliding Window116
When the Bitmask problem arrives live
Stealth Interview is a desktop app for macOS and Windows. It reads the coding problem off your screen, returns a working solution with a step-by-step explanation and its time and space complexity, and transcribes what the interviewer is saying — while staying invisible to screen sharing.