DSA Patterns for Coding Interviews#
Most coding-interview problems are not new. Behind the thousands of questions there are only a few patterns: reusable ideas like “two pointers”, “sliding window” or “BFS”. Learn the pattern once and you can solve every problem that wears it as a costume.
This course teaches 23 patterns, one session each. Every session follows the same shape, so you always know where to look.
Note
What is a pattern, in one line? A named way of thinking that turns a slow brute-force idea into a fast one. Knowing the name helps you recognise the problem in the first minute of an interview.
How each session works#
The big idea: the pattern explained with an everyday story, the way you would explain it to a child.
Spot it when…: the clues in a problem statement that point to this pattern.
The picture: a diagram of the idea.
Step by step: a full trace on a small example, so you see every move.
The template: short Python code you can adapt.
Worked example, variations, common mistakes.
Practice: problems to solve, and a link to open them in the tracker.
Tip
Do the sessions in order. They start with array tricks, move through linked lists, searching, trees and graphs, then finish with recursion-heavy and heap-based patterns.
Practise each pattern in the Interview prep area: take the placement quiz to find where to start, get a daily plan of what to solve and re-solve next, and log every attempt.
Important
Don’t memorise code, memorise the picture. If you can redraw the diagram and say the flow in your own words, the code writes itself. Always check the complexity out loud in an interview.
Arrays and strings
Linked lists and searching
Trees and graphs
Recursion and optimisation