Bit Manipulation LeetCode Problems: All 194,
With Python Solutions

Every problem in this library that LeetCode tags Bit Manipulation. 173 of them carry a complete Python solution, a worked example and the time and space complexity of the approach.

Get Stealth Interview

Easy: 40
Medium: 96
Hard: 58

1 pattern

How Bit Manipulation problems are solved

A tag names the subject, not the method. These pattern hubs cover the techniques that actually solve Bit Manipulation problems — each one explains the approach, gives a Python template and states its complexity.

Bit ManipulationUse XOR, masks and the low-bit trick to replace whole data structures with an integer.

Eyes only

When the Bit Manipulation problem arrives live.

In the live round, Stealth Interview reads the 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 says. It's a desktop app for macOS and Windows, invisible to screen sharing.

Get Stealth Interview See pricing

90%Subscription

python

Please analyze this context and help me answer the question or solve the problem.

Technical interview · 45 minsolution.pyShared editor · Python 3Longest substring without repeatsMediumGiven a string s, return the length of the longest contiguous substring in which every character is unique.s = "abcabcbb"
→ 31def length_of_longest_substring(s: str) -> int:2 last_seen = {}3 left = best = 04 for right, ch in enumerate(s):5 if ch in last_seen and last_seen[ch] >= left:

python

def length_of_longest_substring(s: str) -> int:    last_seen = {}                    # char -> index    left = best = 0    for right, ch in enumerate(s):        if ch in last_seen and last_seen[ch] >= left:            left = last_seen[ch] + 1  # jump past it        last_seen[ch] = right        best = max(best, right - left + 1)    return best    last_seen = {}                    # char -> index

Approach

At each index r, the window's left edge is:

left r = max (left r -1, last[s r] + 1)

Time O(n): each character enters and leaves the window once.
Space O(min(n, k)): k is the size of the character set.

Type your message...

GPT-6.1 Terra

90%Subscription

python

Please analyze this context and help me answer the question or solve the problem.

python

def length_of_longest_substring(s: str) -> int:    last_seen = {}                    # char -> index    left = best = 0    for right, ch in enumerate(s):        if ch in last_seen and last_seen[ch] >= left:            left = last_seen[ch] + 1  # jump past it        last_seen[ch] = right        best = max(best, right - left + 1)    return best    last_seen = {}                    # char -> index

Approach

At each index r, the window's left edge is:

left r = max (left r -1, last[s r] + 1)

Time O(n): each character enters and leaves the window once.
Space O(min(n, k)): k is the size of the character set.

Type your message...

GPT-6.1 TerraClear chat

QuitEscHide+QCapture+PCrop+OSubmit+EnterPress to get answerLeft/Right+Up/Down+

90%Subscription

python

Please analyze this context and help me answer the question or solve the problem.

python

def length_of_longest_substring(s: str) -> int:    last_seen = {}                    # char -> index    left = best = 0    for right, ch in enumerate(s):        if ch in last_seen and last_seen[ch] >= left:            left = last_seen[ch] + 1  # jump past it        last_seen[ch] = right        best = max(best, right - left + 1)    return best    last_seen = {}                    # char -> index

Approach

At each index r, the window's left edge is:

left r = max (left r -1, last[s r] + 1)

Time O(n): each character enters and leaves the window once.
Space O(min(n, k)): k is the size of the character set.

Type your message...

GPT-6.1 TerraClear chat

Primary display

QuitEscHide+QCapture+PCrop+OSubmit+EnterPress to get answerLeft/Right+Up/Down+

Bit Manipulation problems by difficulty

Problems with a complete Python solution are listed first, then by ascending problem number.

Easy (40)

Easy problems
No.	Problem	Topics
0067	Add Binary	Bit Manipulation, Math, String +1
0136	Single Number	Bit Manipulation, Array
0190	Reverse Bits	Bit Manipulation, Divide and Conquer
0191	Number of 1 Bits	Bit Manipulation, Divide and Conquer
0222	Count Complete Tree Nodes	Bit Manipulation, Tree, Binary Search +1
0231	Power of Two	Bit Manipulation, Recursion, Math
0268	Missing Number	Bit Manipulation, Array, Hash Table +3
0338	Counting Bits	Bit Manipulation, Dynamic Programming
0342	Power of Four	Bit Manipulation, Recursion, Math
0389	Find the Difference	Bit Manipulation, Hash Table, String +1
0401	Binary Watch	Bit Manipulation, Backtracking
0405	Convert a Number to Hexadecimal	Bit Manipulation, Math, String
0461	Hamming Distance	Bit Manipulation
0476	Number Complement	Bit Manipulation
0645	Set Mismatch	Bit Manipulation, Array, Hash Table +1
0693	Binary Number with Alternating Bits	Bit Manipulation
0762	Prime Number of Set Bits in Binary Representation	Bit Manipulation, Math
0832	Flipping an Image	Bit Manipulation, Array, Two Pointers +2
0868	Binary Gap	Bit Manipulation
1009	Complement of Base 10 Integer	Bit Manipulation
1018	Binary Prefix Divisible By 5	Bit Manipulation, Array
1342	Number of Steps to Reduce a Number to Zero	Bit Manipulation, Math
1356	Sort Integers by The Number of 1 Bits	Bit Manipulation, Array, Counting +1
1486	XOR Operation in an Array	Bit Manipulation, Math
1684	Count the Number of Consistent Strings	Bit Manipulation, Array, Hash Table +2
1720	Decode XORed Array	Bit Manipulation, Array
1763	Longest Nice Substring	Bit Manipulation, Hash Table, String +2
1863	Sum of All Subset XOR Totals	Bit Manipulation, Array, Math +3
2032	Two Out of Three	Bit Manipulation, Array, Hash Table
2206	Divide Array Into Equal Pairs	Bit Manipulation, Array, Hash Table +1
2220	Minimum Bit Flips to Convert Number	Bit Manipulation
2351	First Letter to Appear Twice	Bit Manipulation, Hash Table, String +1
2506	Count Pairs Of Similar Strings	Bit Manipulation, Array, Hash Table +2
2595	Number of Even and Odd Bits	Bit Manipulation
2859	Sum of Values at Indices With K Set Bits	Bit Manipulation, Array
2869	Minimum Operations to Collect Elements	Bit Manipulation, Array, Hash Table
2917	Find the K-or of an Array	Bit Manipulation, Array
2932	Maximum Strong Pair XOR I	Bit Manipulation, Trie, Array +2
2980	Check if Bitwise OR Has Trailing Zeros	Bit Manipulation, Array
0266	Palindrome PermutationPremium	Bit Manipulation, Hash Table, String

Medium (96)

Medium problems
No.	Problem	Topics
0029	Divide Two Integers	Bit Manipulation, Math
0078	Subsets	Bit Manipulation, Array, Backtracking
0089	Gray Code	Bit Manipulation, Math, Backtracking
0090	Subsets II	Bit Manipulation, Array, Backtracking
0137	Single Number II	Bit Manipulation, Array
0187	Repeated DNA Sequences	Bit Manipulation, Hash Table, String +3
0201	Bitwise AND of Numbers Range	Bit Manipulation
0260	Single Number III	Bit Manipulation, Array
0287	Find the Duplicate Number	Bit Manipulation, Array, Two Pointers +1
0318	Maximum Product of Word Lengths	Bit Manipulation, Array, String
0371	Sum of Two Integers	Bit Manipulation, Math
0393	UTF-8 Validation	Bit Manipulation, Array
0397	Integer Replacement	Greedy, Bit Manipulation, Memoization +1
0421	Maximum XOR of Two Numbers in an Array	Bit Manipulation, Trie, Array +1
0464	Can I Win	Bit Manipulation, Memoization, Math +3
0473	Matchsticks to Square	Bit Manipulation, Array, Dynamic Programming +2
0477	Total Hamming Distance	Bit Manipulation, Array, Math
0491	Non-decreasing Subsequences	Bit Manipulation, Array, Hash Table +1
0526	Beautiful Arrangement	Bit Manipulation, Array, Dynamic Programming +2
0638	Shopping Offers	Bit Manipulation, Memoization, Array +3
0672	Bulb Switcher II	Bit Manipulation, Depth-First Search, Breadth-First Search +1
0698	Partition to K Equal Sum Subsets	Bit Manipulation, Memoization, Array +3
0756	Pyramid Transition Matrix	Bit Manipulation, Hash Table, String +1
0779	K-th Symbol in Grammar	Bit Manipulation, Recursion, Math
0784	Letter Case Permutation	Bit Manipulation, String, Backtracking
0861	Score After Flipping Matrix	Greedy, Bit Manipulation, Array +1
0898	Bitwise ORs of Subarrays	Bit Manipulation, Array, Dynamic Programming
1016	Binary String With Substrings Representing 1 To N	Bit Manipulation, Hash Table, String +1
1177	Can Make Palindrome from Substring	Bit Manipulation, Array, Hash Table +2
1238	Circular Permutation in Binary Representation	Bit Manipulation, Math, Backtracking
1239	Maximum Length of a Concatenated String with Unique Characters	Bit Manipulation, Array, String +1
1310	XOR Queries of a Subarray	Bit Manipulation, Array, Prefix Sum
1318	Minimum Flips to Make a OR b Equal to c	Bit Manipulation
1371	Find the Longest Substring Containing Vowels in Even Counts	Bit Manipulation, Hash Table, String +1
1386	Cinema Seat Allocation	Greedy, Bit Manipulation, Array +1
1404	Number of Steps to Reduce a Number in Binary Representation to One	Bit Manipulation, String, Simulation
1442	Count Triplets That Can Form Two Arrays of Equal XOR	Bit Manipulation, Array, Hash Table +2
1457	Pseudo-Palindromic Paths in a Binary Tree	Bit Manipulation, Tree, Depth-First Search +2
1461	Check If a String Contains All Binary Codes of Size K	Bit Manipulation, Hash Table, String +2
1525	Number of Good Ways to Split a String	Bit Manipulation, Hash Table, String +1
1558	Minimum Numbers of Function Calls to Make Target Array	Greedy, Bit Manipulation, Array
1680	Concatenation of Consecutive Binary Numbers	Bit Manipulation, Math, Simulation
1734	Decode XORed Permutation	Bit Manipulation, Array
1738	Find Kth Largest XOR Coordinate Value	Bit Manipulation, Array, Divide and Conquer +5
1829	Maximum XOR for Each Query	Bit Manipulation, Array, Prefix Sum
1915	Number of Wonderful Substrings	Bit Manipulation, Hash Table, String +1
1930	Unique Length-3 Palindromic Subsequences	Bit Manipulation, Hash Table, String +1
1947	Maximum Compatibility Score Sum	Bit Manipulation, Array, Dynamic Programming +2
1986	Minimum Number of Work Sessions to Finish the Tasks	Bit Manipulation, Array, Dynamic Programming +2
2002	Maximum Product of the Length of Two Palindromic Subsequences	Bit Manipulation, String, Dynamic Programming +2
2044	Count Number of Maximum Bitwise-OR Subsets	Bit Manipulation, Array, Backtracking +1
2135	Count Words Obtained After Adding a Letter	Bit Manipulation, Array, Hash Table +2
2212	Maximum Points in an Archery Competition	Bit Manipulation, Array, Backtracking +1
2275	Largest Combination With Bitwise AND Greater Than Zero	Bit Manipulation, Array, Hash Table +1
2305	Fair Distribution of Cookies	Bit Manipulation, Array, Dynamic Programming +2
2317	Maximum XOR After Operations	Bit Manipulation, Array, Math
2397	Maximum Rows Covered by Columns	Bit Manipulation, Array, Backtracking +2
2401	Longest Nice Subarray	Bit Manipulation, Array, Sliding Window
2411	Smallest Subarrays With Maximum Bitwise OR	Bit Manipulation, Array, Binary Search +1
2419	Longest Subarray With Maximum Bitwise AND	Bit Manipulation, Brainteaser, Array
2425	Bitwise XOR of All Pairings	Bit Manipulation, Brainteaser, Array
2429	Minimize XOR	Greedy, Bit Manipulation
2433	Find The Original Array of Prefix Xor	Bit Manipulation, Array
2438	Range Product Queries of Powers	Bit Manipulation, Array, Prefix Sum
2527	Find Xor-Beauty of Array	Bit Manipulation, Array, Math
2546	Apply Bitwise Operations to Make Strings Equal	Bit Manipulation, String
2564	Substring XOR Queries	Bit Manipulation, Array, Hash Table +1
2568	Minimum Impossible OR	Bit Manipulation, Brainteaser, Array
2571	Minimum Operations to Reduce an Integer to 0	Greedy, Bit Manipulation, Dynamic Programming
2572	Count the Number of Square-Free Subsets	Bit Manipulation, Array, Math +2
2588	Count the Number of Beautiful Subarrays	Bit Manipulation, Array, Hash Table +1
2657	Find the Prefix Common Array of Two Arrays	Bit Manipulation, Array, Hash Table
2680	Maximum OR	Greedy, Bit Manipulation, Array +1
2683	Neighboring Bitwise XOR	Bit Manipulation, Array
2708	Maximum Strength of a Group	Greedy, Bit Manipulation, Array +4
2741	Special Permutations	Bit Manipulation, Array, Dynamic Programming +1
2749	Minimum Operations to Make the Integer Zero	Bit Manipulation, Brainteaser, Enumeration
2857	Count Pairs of Points With Distance k	Bit Manipulation, Array, Hash Table
2871	Split Array Into Maximum Number of Subarrays	Greedy, Bit Manipulation, Array
2939	Maximum Xor Product	Greedy, Bit Manipulation, Math
2997	Minimum Number of Operations to Make Array XOR Equal to K	Bit Manipulation, Array
0320	Generalized AbbreviationPremium	Bit Manipulation, String, Backtracking
0351	Android Unlock PatternsPremium	Bit Manipulation, Dynamic Programming, Backtracking +1
0751	IP to CIDRPremium	Bit Manipulation, String
0957	Prison Cells After N Days	Bit Manipulation, Array, Hash Table +1
1066	Campus Bikes IIPremium	Bit Manipulation, Array, Dynamic Programming +2
1256	Encode NumberPremium	Bit Manipulation, Math, String
1506	Find Root of N-Ary TreePremium	Bit Manipulation, Tree, Depth-First Search +1
1908	Game of NimPremium	Bit Manipulation, Brainteaser, Array +3
2128	Remove All Ones With Row and Column FlipsPremium	Bit Manipulation, Array, Math +1
2152	Minimum Number of Lines to Cover PointsPremium	Bit Manipulation, Geometry, Array +5
2174	Remove All Ones With Row and Column Flips IIPremium	Bit Manipulation, Breadth-First Search, Array +1
2184	Number of Ways to Build Sturdy Brick WallPremium	Bit Manipulation, Array, Dynamic Programming +1
2505	Bitwise OR of All Subsequence SumsPremium	Bit Manipulation, Brainteaser, Array +2
2802	Find The K-th Lucky NumberPremium	Bit Manipulation, Math, String
2992	Number of Self-Divisible PermutationsPremium	Bit Manipulation, Array, Math +4

Hard (58)

Hard problems
No.	Problem	Topics
0691	Stickers to Spell Word	Bit Manipulation, Memoization, Array +5
0782	Transform to Chessboard	Bit Manipulation, Array, Math +1
0805	Split Array With Same Average	Bit Manipulation, Array, Math +2
0810	Chalkboard XOR Game	Bit Manipulation, Brainteaser, Array +2
0847	Shortest Path Visiting All Nodes	Bit Manipulation, Breadth-First Search, Graph +2
0864	Shortest Path to Get All Keys	Bit Manipulation, Breadth-First Search, Array +1
0943	Find the Shortest Superstring	Bit Manipulation, Array, String +2
0980	Unique Paths III	Bit Manipulation, Array, Backtracking +1
0982	Triples with Bitwise AND Equal To Zero	Bit Manipulation, Array, Hash Table
0995	Minimum Number of K Consecutive Bit Flips	Bit Manipulation, Queue, Array +2
0996	Number of Squareful Arrays	Bit Manipulation, Array, Hash Table +4
1125	Smallest Sufficient Team	Bit Manipulation, Array, Dynamic Programming +1
1178	Number of Valid Words for Each Puzzle	Bit Manipulation, Trie, Array +2
1255	Maximum Score Words Formed by Letters	Bit Manipulation, Array, Hash Table +5
1284	Minimum Number of Flips to Convert Binary Matrix to Zero Matrix	Bit Manipulation, Breadth-First Search, Array +2
1349	Maximum Students Taking Exam	Bit Manipulation, Array, Dynamic Programming +2
1434	Number of Ways to Wear Different Hats to Each Other	Bit Manipulation, Array, Dynamic Programming +1
1483	Kth Ancestor of a Tree Node	Bit Manipulation, Tree, Depth-First Search +4
1494	Parallel Courses II	Bit Manipulation, Graph, Dynamic Programming +1
1521	Find a Value of a Mysterious Function Closest to Target	Bit Manipulation, Segment Tree, Array +1
1542	Find Longest Awesome Substring	Bit Manipulation, Hash Table, String
1595	Minimum Cost to Connect Two Groups of Points	Bit Manipulation, Array, Dynamic Programming +2
1601	Maximum Number of Achievable Transfer Requests	Bit Manipulation, Array, Backtracking +1
1611	Minimum One Bit Operations to Make Integers Zero	Bit Manipulation, Memoization, Dynamic Programming
1617	Count Subtrees With Max Distance Between Cities	Bit Manipulation, Tree, Dynamic Programming +2
1655	Distribute Repeating Integers	Bit Manipulation, Array, Dynamic Programming +2
1659	Maximize Grid Happiness	Bit Manipulation, Memoization, Dynamic Programming +1
1681	Minimum Incompatibility	Bit Manipulation, Array, Dynamic Programming +1
1707	Maximum XOR With an Element From Array	Bit Manipulation, Trie, Array
1723	Find Minimum Time to Finish All Jobs	Bit Manipulation, Array, Dynamic Programming +2
1755	Closest Subsequence Sum	Bit Manipulation, Array, Two Pointers +3
1787	Make the XOR of All Segments Equal to Zero	Bit Manipulation, Array, Dynamic Programming
1799	Maximize Score After N Operations	Bit Manipulation, Array, Math +4
1803	Count Pairs With XOR in a Range	Bit Manipulation, Trie, Array
1815	Maximum Number of Groups Getting Fresh Donuts	Bit Manipulation, Memoization, Array +2
1835	Find XOR Sum of All Pairs Bitwise AND	Bit Manipulation, Array, Math
1879	Minimum XOR Sum of Two Arrays	Bit Manipulation, Array, Dynamic Programming +1
1994	The Number of Good Subsets	Bit Manipulation, Array, Hash Table +5
2035	Partition Array Into Two Arrays to Minimize Sum Difference	Bit Manipulation, Array, Two Pointers +4
2151	Maximum Good People Based on Statements	Bit Manipulation, Array, Backtracking +1
2157	Groups of Strings	Bit Manipulation, Union Find, String
2172	Maximum AND Sum of Array	Bit Manipulation, Array, Dynamic Programming +1
2306	Naming a Company	Bit Manipulation, Array, Hash Table +2
2322	Minimum Score After Removals on a Tree	Bit Manipulation, Tree, Depth-First Search +1
2354	Number of Excellent Pairs	Bit Manipulation, Array, Hash Table +1
2732	Find a Good Subset of the Matrix	Bit Manipulation, Array, Hash Table +1
2791	Count Paths That Can Form a Palindrome in a Tree	Bit Manipulation, Tree, Depth-First Search +2
2835	Minimum Operations to Form Subsequence With Target Sum	Greedy, Bit Manipulation, Array
2836	Maximize Value of Function in a Ball Passing Game	Bit Manipulation, Array, Dynamic Programming
2897	Apply Operations on Array to Maximize Sum of Squares	Greedy, Bit Manipulation, Array +1
2920	Maximum Points After Collecting Coins From All Nodes	Bit Manipulation, Tree, Depth-First Search +3
2935	Maximum Strong Pair XOR II	Bit Manipulation, Trie, Array +2
2959	Number of Possible Sets of Closing Branches	Bit Manipulation, Graph, Enumeration +2
0411	Minimum Unique Word AbbreviationPremium	Bit Manipulation, Array, String +1
0465	Optimal Account BalancingPremium	Bit Manipulation, Array, Dynamic Programming +2
1938	Maximum Genetic Difference Query	Bit Manipulation, Depth-First Search, Trie +2
2247	Maximum Cost of Trip With K HighwaysPremium	Bit Manipulation, Graph, Dynamic Programming +1
2403	Minimum Time to Kill All MonstersPremium	Bit Manipulation, Array, Dynamic Programming +1

How Bit Manipulation problems are solved

When the Bit Manipulation problem arrives live.

Approach

Approach

Approach

Bit Manipulation problems by difficulty

Easy (40)40

Medium (96)96

Hard (58)58

Keep exploring

Easy (40)

Medium (96)

Hard (58)