Understand what data structures and algorithms are and why they matter in interviews.
Data Structures are ways of organizing and storing data so it can be accessed and modified efficiently. Algorithms are step-by-step procedures to solve problems. Together, DSA forms the foundation of software engineering and is the core topic tested in technical interviews at every major tech company.
N/A — this is a conceptual topic
N/A — this is a conceptual topic
Learn the core patterns in this topic. Each block explains when to use the pattern, the intuition behind it, and a compact code example.
organizes data for efficient access.
const arr = [1,2,3]; arr[0] // O(1)
step-by-step instructions to solve a problem.
sort → binary search
interviewers test problem-solving and code efficiency, not just syntax
how runtime grows with input size.
one loop = O(n)
how memory grows with input size.
storing n items = O(n)
most problems reuse ~15 patterns: sliding window, two pointers, DFS, DP, etc.