The ultimate recursion guide! Master basics, solve real-world problems, and get interview-ready in hours with FAANG engineers’ proven strategies.

If you’ve ever struggled with solving coding problems using recursion, or if you need to brush up your recursion skills for an interview, this course is for you! We will start with the basics of recursion before we practice solving actual coding problems. You’ll have access to detailed explanations and visualizations for each problem to help you along the way.

By the time you have completed this course, you’ll be able to use all the concepts of recursion to solve complex, real-world problems. We hope that this course will help you ace all the recursion related questions during interviews at top tech companies!

Recursion for Coding Interviews in Python

def recursiveLength(testVariable) : 	
	# Base Case	
	if (testVariable == "") : 
		return 0

	# Recursive Case
	else : 
		return 1 + recursiveLength(testVariable[1:]) 
	
# Driver Code 
testVariable = "Educative"
print (recursiveLength(testVariable)) 

## Explanation

The **base case** for this solution will test for an empty string `""`. If the string is empty we return $0$.

For the recursive case, we call another instance of the same function, but we remove the first element. When the child element returns the length, we add $1$ to the returned length.

The recursive case is based on the paradigm that the length of the complete string is $1$ more than the length of the string after removing one element.

> $length\:of\:string \: from \: index \: i \: to \: n-1 = 1 + length\:of\:string \: from \: index \: i - 1 \: to \: n-1$.

Let's take a look at an illustration of this problem:

This review provides a detailed analysis of the solution to find the length of a string recursively.

Recursion Fundamentals

Iteration Vs. Recursion

Recursion with Numbers

Recursion with Strings

Recursion with Arrays

Recursion with Data Structures

Conclusion

Solution Review: Length of a String

Solution: Using Recursion

Explanation