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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 fibonacci(testVariable):
  fn0 = 0
  fn1 = 1
    
  for i in range(0, testVariable):
    temp = fn0 + fn1

    # Setting variables for next iteration
    fn0 = fn1
    fn1 = temp

  return fn0

# Driver Code
testVariable = 7
print(fibonacci(testVariable))

## Explanation
In the iterative method, we keep track of the two previous elements using the variables `fn0` and `fn1`.
Initially, the values of the two variables are:
```python
fn0 = 0
fn1 = 1
```
However, with each iteration, the values are updated as follows:

def fibonacci(testVariable):
 # Base Case
 if testVariable <= 1 :
 return testVariable
 
 # Recursive Case
 return(fibonacci(testVariable - 1) + fibonacci(testVariable - 2))

# Driver Code
testVariable = 7
print(fibonacci(testVariable))

## Explanation:

In the code above, the function `fibonacci()` is a recursive function, since it calls itself in the function body.

The **base case** of the function **(line number 3)** deals with the two initial values: for index $0$, value is $0$; for index $1$ the value is $1$.
```python
 if testVariable <= 1 :
 return testVariable
```
However, in the **recursive method**, the parent function recursively calls itself twice with $n-1$ and $n-2$. The input arguments correspond to the equation used for finding a general term in the **Fibonacci sequence**. 

 $F$n $=F$n-2$+F$n-1

Let's look at the code flow:

This review provides a detailed analysis of how to find the corresponding element at a given index in the Fibonacci series.

Recursion Fundamentals

Iteration Vs. Recursion

Recursion with Numbers

Recursion with Strings

Recursion with Arrays

Recursion with Data Structures

Conclusion

Solution Review: Corresponding Fibonacci Number

Solution #1: Iterative Method

Explanation

Solution #2: Recursive Method

Explanation: