Data Structures and Algorithms in C++ For Coding Interview

Explore the two sum problem: find two numbers that add to a target, return their indices with distinct elements, and learn the naïve O(n^2) double-loop solution with examples.

Sort the numbers with their original indices using a pair, then apply a two-pointer scan to find two values that sum to the target, returning their original indices.

Implement the O(n^2) naive solution in C++, initializing max and current lengths, counting consecutive ones in nums, updating the maximum, and validating an accepted submission.

Identify the maximum product of any three numbers in a given integer array (length up to 10^4) and output that product, ensuring it fits in a 32-bit integer.

Explore a naive approach to maximize the product of three numbers by checking all triplets with three nested loops, detailing its O(n^3) complexity and preparing for optimization.

Sort the array to achieve an O(n log n) solution for maximizing the product of three numbers, handling negatives by using the largest three or two smallest with the largest.

Implement an O(n log n) maximum product solution in C++, sorting nums, computing P1 and P2, then returning their maximum.

Implement an O(n) solution that tracks the three largest and two smallest numbers, computes two product candidates, and returns their maximum.

Explore the problem of valid parentheses by analyzing a string containing open and close parentheses, curly brackets, and brackets to determine balance, and compare recursive quadratic-time and linear-time stack-based solutions.

Explore a recursive algorithm for the valid parentheses problem that runs in O(n^2) time, using removal of open-close pairs to test balance and returning true for empty strings.

Explore how to use a hash map to achieve an average-case O(n) solution for detecting nearby duplicates within distance k, with insert and update operations and hashing concepts.