Problem Solving Approaches and Patterns

This module covers systematic approaches to solving coding problems and common algorithmic patterns that appear frequently in interviews and real-world code.

Why this matters

Having a structured approach to problem-solving prevents you from getting stuck and helps you identify which pattern to apply. These patterns are reusable templates that solve entire classes of problems.

Sections

Problem Solving Strategy - How to understand, break down, and solve problems systematically
Frequency Counter Pattern - Using objects/maps to count occurrences
Multiple Pointers Pattern - Using two or more pointers to traverse data
Sliding Window Pattern - Efficiently processing subarrays/substrings
Divide and Conquer Pattern - Breaking problems into smaller subproblems

Quick reference

Pattern	Use Case	Time Complexity	Example Problems
Frequency Counter	Counting occurrences, comparing collections	O(n)	Anagrams, duplicates
Multiple Pointers	Sorted arrays, pairs, searching	O(n)	Two sum, unique values
Sliding Window	Subarrays/substrings, consecutive elements	O(n)	Max subarray sum, longest substring
Divide and Conquer	Sorted data, recursive problems	O(log n) or O(n log n)	Binary search, merge sort