bit manipulation

Divide Two Integers

Solve Divide Two Integers by turning repeated subtraction into bit-shifted chunk subtraction with careful sign and overf…

Add Binary

Add Binary involves summing two binary strings and returning the result as a binary string using math and string manipul…

Subsets

Generate all subsets of a set of unique integers using backtracking with pruning to avoid duplicates.

Gray Code

Generate an n-bit Gray Code sequence using backtracking with pruning and bit manipulation techniques.

Subsets II

Subsets II problem asks to generate unique subsets from an array with possible duplicates using backtracking search with…

Single Number

Solve the Single Number problem using an efficient approach with constant space and linear time complexity.

Single Number II

Find the single element in an array where every other element appears three times, using bit manipulation and constant s…

Repeated DNA Sequences

Solve Repeated DNA Sequences by sliding a length-10 window and tracking seen patterns with a hash set or bitmask.

Reverse Bits

Reverse a 32-bit unsigned integer by manipulating bits efficiently using a divide and conquer approach with careful bit …

Number of 1 Bits

Number of 1 Bits is a classic bit manipulation problem where clearing the lowest set bit gives the cleanest count.

Bitwise AND of Numbers Range

Use shared high bits and bit clearing to solve Bitwise AND of Numbers Range without scanning every value.

Count Complete Tree Nodes

Count Complete Tree Nodes efficiently by leveraging binary-tree traversal, exploiting completeness, and applying bit man…

Power of Two

Determine if a given integer is a power of two using efficient math and bit manipulation techniques with optional recurs…

Single Number III

Find the two unique numbers in an array where all other numbers appear exactly twice using bit manipulation efficiently.

Missing Number

Find the missing number in an array containing distinct numbers in the range [0, n].

Find the Duplicate Number

The problem involves finding the duplicate number in an array of integers, using a binary search approach over the valid…

Maximum Product of Word Lengths

The problem requires finding the maximum product of lengths of two words from an array, where the words don't share comm…

Counting Bits

Compute the number of 1 bits for every integer from 0 to n using state transition dynamic programming for efficiency.

Power of Four

Determine if a given integer is a power of four using math insights and bit manipulation tricks efficiently in code.

Sum of Two Integers

Solve the Sum of Two Integers problem using bit manipulation and math to avoid using the operators + and -.

Find the Difference

Find the Difference involves identifying the additional letter in one string compared to another, emphasizing hash table…

UTF-8 Validation

Determine if an integer array represents valid UTF-8 encoding based on its byte sequences using bit manipulation.

Integer Replacement

Find the minimum number of operations to reduce a number to 1 by applying specific operations, using state transition dy…

Binary Watch

Binary Watch involves generating possible times on a binary watch given a number of turned-on LEDs.