Algorithm Study

A Python solution using Kadane's algorithm to find the maximum sum of a contiguous subarray

A Python backtracking solution to Combination Sum using a start index and pruning

A Python solution that counts 1 bits by repeatedly dividing by 2

A two-pointer Python solution for checking palindromes after normalizing alphanumeric characters

A DFS Python solution for checking whether a BST is built with valid value ranges

A 3Sum solution using sorting and a two-sum-style hash map approach.

A left-product and right-product solution for Product of Array Except Self.

A recursion and memoization write-up for the Climbing Stairs problem.

A comparison of sorting and character counting for the Valid Anagram problem.

Solving the rob-or-skip choice with top-down DP and memoization

Using a set to count each consecutive sequence only from its starting point

Using frequency counting and bucket arrays to return the top k frequent elements

Comparing brute force, two-pass hash map, and one-pass hash map approaches for Two Sum

Comparing brute force, sorting, and hash set approaches for duplicate detection

Solving BST range sum through BFS, DFS, and prefix sums

Why a modified Bellman-Ford approach fits the K-stop constraint better, and some implementation notes