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++

```C++
if(startIndex >= len)
        return;
````

```C++
if(startIndex <= len)
 return;
````

```C++
if(startIndex >= len/2)
        return;
````

The task is to print the array using recursion.
```C++
void printArray(int array[], int startIndex, int len)
{
 cout<<arr[startIndex]<<"\t";
 
 // Recursively calling printArray to print next element in the array
 printArrayarray, startIndex + 1, len);
}
```

What should be the base case of the following code?

The task is to print the array using recursion.
<pre><code class="language-C++">void printArray(int array[], int startIndex, int len)
{
 cout&lt;&lt;arr[startIndex]&lt;&lt;&quot;\t&quot;;
 
 // Recursively calling printArray to print next element in the array
 printArrayarray, startIndex + 1, len);
}
</code></pre>
What should be the base case of the following code?

return sum + arraySum(array, startIndex + 1, endIndex);

return sum + arraySum(array, startIndex + 1, endIndex+1);

The task is to print the sum of array elements using recursion.
```C++
int arraySum( int array[], int startIndex, int endIndex)
{	
	int sum = 0, temp;
  //base case
	if(startIndex == endIndex)
		return array[startIndex];
	else
		//recursive case
}
```
What should be the recursive case of the following code?

The task is to print the sum of array elements using recursion.
<pre><code class="language-C++">int arraySum( int array[], int startIndex, int endIndex)
{	
	int sum = 0, temp;
 //base case
	if(startIndex == endIndex)
		return array[startIndex];
	else
		//recursive case
}
</code></pre>
What should be the recursive case of the following code?

Solve this Quiz!

Solve this Quiz!

This lesson will check your knowledge of recursion with arrays.

Recursion Fundamentals

Recursion with Numbers

Recursion With Strings

Recursion With Arrays

Recursion with Data Structures

Quick Quiz on Recursion with Arrays!