math

Add Two Numbers

Add Two Numbers requires careful linked-list pointer manipulation to sum digits while handling carries efficiently in in…

Reverse Integer

Reverse Integer challenges you to invert the digits of a signed 32-bit integer, handling overflow and negative values ca…

Palindrome Number

Determine if a given integer reads the same forward and backward using a math-driven solution strategy without convertin…

Integer to Roman

Convert a given integer to its Roman numeral representation using hash table mapping and decimal place math operations e…

Roman to Integer

Convert a Roman numeral string into an integer using a hash table and mathematical principles to determine value order.

Divide Two Integers

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

Multiply Strings

Multiply Strings requires simulating integer multiplication using only string operations without direct numeric conversi…

Rotate Image

Rotate an n x n matrix 90 degrees clockwise in-place using array manipulation and mathematical indexing techniques effic…

Pow(x, n)

Calculate x to the power n efficiently using recursion and exponentiation, handling negative powers and large inputs saf…

Permutation Sequence

Find the kth permutation sequence of a set of numbers using math and recursion to efficiently compute the result.

Unique Paths

Calculate the number of unique paths for a robot to move on an m x n grid with only right and down movements.

Plus One

Given a number as an array of digits, increment it by one and return the updated array of digits.

Add Binary

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

Sqrt(x)

Solve the Sqrt(x) problem using binary search to find the integer square root of a number without built-in operators.

Climbing Stairs

Climbing Stairs is a classic dynamic programming problem where you calculate distinct ways to reach the top using step t…

Gray Code

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

Unique Binary Search Trees

Given n nodes, calculate the number of unique binary search trees (BSTs) that can be formed with values from 1 to n.

Max Points on a Line

Find the maximum number of points on a straight line in a 2D plane using array scanning and hash lookup.

Evaluate Reverse Polish Notation

Compute the result of an arithmetic expression in Reverse Polish Notation using a stack to manage operands efficiently.

Fraction to Recurring Decimal

Convert a fraction into a decimal, handling repeating decimals with parentheses around the repeating part.

Excel Sheet Column Title

Convert a positive integer to its corresponding Excel column title using base-26 math and string manipulation efficientl…

Excel Sheet Column Number

This problem requires converting an Excel column title into its corresponding column number by applying a math and strin…

Factorial Trailing Zeroes

Given a number n, find how many trailing zeroes are in n! using a math-driven approach.

Rotate Array

Rotate Array challenges you to shift elements right by k steps using precise two-pointer scanning and invariant tracking…