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++

replace(text.substr(1),index,lenString-1)

The task is to replace all occurrences of 'e' with 'a' using recursion.
```C++
void replace(string& text, int index, int lenString)
{	

  //base case
	if(index == lenString-1)
		return
	else
		//recursive case
}
```
What should be the recursive case of the following code?

The task is to replace all occurrences of ‘e’ with ‘a’ using recursion.
<pre><code class="language-C++">void replace(string&amp; text, int index, int lenString)
{	

 //base case
	if(index == lenString-1)
		return
	else
		//recursive case
}
</code></pre>
What should be the recursive case of the following code?

The task is to remove all spaces in a string
```C++
void removeSpace(string& text, int startIndex, int len)
{
		//Base Case?
 
    // Recursively calling the function
    if(text[startIndex]==' ')
  		removeSpace(text, startIndex, len-1);
  else{
  		removeSpace(text,startIndex+1,len);
  }
}
```

What should be the base case of the following code?

The task is to remove all spaces in a string
<pre><code class="language-C++">void removeSpace(string&amp; text, int startIndex, int len)
{
		//Base Case?
 
 // Recursively calling the function
 if(text[startIndex]==' ')
 		removeSpace(text, startIndex, len-1);
 else{
 		removeSpace(text,startIndex+1,len);
 }
}
</code></pre>
What should be the base case of the following code?

This quiz will test your understanding of recursion in strings

Recursion Fundamentals

Recursion with Numbers

Recursion With Strings

Recursion With Arrays

Recursion with Data Structures

Quick Quiz on Recursion with Strings!