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Learning Path
Introduction to DSABig O & ComplexityArrays & StringsHashMaps & SetsLinked ListsStacks & QueuesRecursion & BacktrackingSearching & SortingTrees & TriesGreedy & IntervalsGraphsDynamic Programming

Introduction to DSA

beginner

What is Data Structures & Algorithms?

Data Structures

A data structure is just a way of organizing data on a computer. Think of it like organizing your files. You could throw everything into one big folder (an array). You could label things with sticky notes so you can find them instantly (a hash map). You could stack papers in a pile where you can only grab the top one (a stack). You could arrange things in a hierarchy like a family tree (a tree).

Different data structures are good at different things. Some are fast at adding data. Some are fast at searching. Some keep things in order. Choosing the right one is the first step to writing good code.

Algorithms

An algorithm is a set of steps to solve a problem. If you have a phone book and need to find Smith, you would not read every name from the start. You would flip to the middle, see if Smith is before or after, then repeat. That is binary search, and it is an algorithm.

Most problems can be solved in more than one way. The difference is often speed. An algorithm that takes 1 millisecond vs one that takes 10 seconds is the difference between a working app and a broken one.

Why learn this stuff?

  • You will write code that runs faster and uses less memory.
  • You will learn to think through problems before writing code.
  • Many companies ask DSA questions in interviews for a reason: it tests how you approach problems, not what you memorized.
  • Once you know the patterns, a lot of coding problems become variations of things you already know.

What this course covers

There are 11 modules, ordered so that each one builds on the previous. You can go through them in order, or jump around once you unlock them.

How each module works

Learn. Read through the theory sections with code examples and visualizations.

Practice. Solve problems that test your understanding. Start with easy ones, work up to harder ones.

Exam. Pass a short quiz to lock in the module. Once you pass, the next module unlocks.

Ready to start?

Click “Mark as Read” below to unlock Module 1.