DSA & Programming Logic Problems
Learn core data structures and algorithmic patterns through comprehensive multi-approach explanations, underlying logic walkthroughs, asymptotic complexities, and multi-language code implementations connected to ToolMight's interactive visualizers.
Two Sum
Find the two numbers in an array that sum up to a target value. The quintessential problem for learning how to trade memory for speed using a Hash Map.
Linear Search
The foundational search algorithm for unsorted collections. Scans elements one by one until a match is found or the list is exhausted.
Binary Search
Locate a target value in a sorted array in O(log n) logarithmic time. Like opening a dictionary in the middle, each comparison eliminates half the remaining items.
Valid Parentheses
Verify that code brackets (), {}, and [] are properly closed and nested in order. This is the exact algorithm compilers, linters, and IDEs use to detect syntax errors in real-time.
Reverse Linked List
Reverse the directional arrows of a singly linked list in-place. The classic test of reference manipulation and memory pointer management.
Best Time to Buy and Sell Stock
Determine the maximum single-transaction profit from daily stock prices. A classic demonstration of how tracking a running minimum transforms an O(n²) pair search into an O(n) single pass.
Valid Anagram
Determine whether two strings have the exact same character frequencies. A core problem demonstrating the power of fixed-size frequency buckets over O(n log n) sorting.
Climbing Stairs
Count the distinct ways to reach the top of an n-step staircase when hopping 1 or 2 steps at a time. The premier gentle introduction to Dynamic Programming and state transition.
Invert Binary Tree
Mirror-flip a binary tree so every left subtree swaps with the right subtree. The quintessential problem for mastering tree recursion and depth-first traversal.
Maximum Subarray (Kadane's Algorithm)
Find the contiguous slice of an array that yields the largest sum. Kadane's algorithm demonstrates the art of shedding negative historical baggage in O(n) linear time.
Search in Rotated Sorted Array
Search a rotated sorted array in O(log n) time. A masterclass in applying binary search when global order is broken: at least one half is always guaranteed to be sorted.