The ultimate guide to recursion interviews. Developed by FAANG engineers, practice with real-world C++ problems, interactive code playgrounds, and get interview-ready in just a few hours.

If you’ve ever struggled with solving coding problems using recursion, or if you’ve just got an interview coming up and want to brush up on your knowledge, you’ll definitely find this course helpful.
 
You’ll start with the basics of what recursion is and why it’s important before diving into what it looks like in practice. You’ll see how recursion can help you solve a variety of different math, string, and data structure problems, using interactive code playgrounds you can execute directly in your browser. You’ll have access to detailed explanations and visualizations for each problem to help you along the way.  
 
By the time you’re done, you’ll be able to use what you’ve learned to solve complex real-world problems, and even advance more easily through your interviews at top tech companies.

Recursion for Coding Interviews in C++

## What is Topological Sort?

**Topological Sort** is a way to order a **directed acyclic** graph. A **directed** graph is one that has arrows that are either *incoming* or *outgoing* meaning they have direction. An **acyclic** graph is one that has *no cycles*, i.e., a node is not reachable from its own ancestors. A topological sort takes such a graph and finds the order of the nodes so that it **always** starts from a node with no incoming edges and then traverses its adjacent nodes. Note that this time, the current node is printed first and then its neighbors are printed. The illustration below will help you understand this concept better. 

# What is Topological Sort?

**Topological Sort** is a way to order a **directed acyclic** graph. A **directed** graph is one that has arrows that are either *incoming* or *outgoing* meaning they have direction. An **acyclic** graph is one that has *no cycles*, i.e., a node is not reachable from its own ancestors. A topological sort takes such a graph and finds the order of the nodes so that it **always** starts from a node with no incoming edges and then traverses its adjacent nodes. Note that this time, the current node is printed first and then its neighbors are printed. The illustration below will help you understand this concept better. 

This lesson will teach you how to write a recursive code for topological sorting in graphs.

Recursion Fundamentals

Recursion with Numbers

Recursion With Strings

Recursion With Arrays

Recursion with Data Structures

Topological Sort in Graphs

What is Topological Sort?