Recursive Functions - Lab

Introduction

Now that you've seen a little preview of recursive functions, it's time to give them a try!

Objectives

You will be able to:

• Understand and use the concept of a recursive function
• Understand scope in the context of recursive functions
• Understand and compare depth first versus breadth first searches

Fibonacci

The Fibonacci sequence starts off: 1,1,2,3,5,8,13,21,34,...

Each number is the sum of the two preceding. Write a recursive function that calculates the nth number of the Fibonacci sequence. For example, our sequence above would correspond to:

fib(1) = 1 #The 1st element in the sequence is 1 fib(2) = 1 #The 2nd element in the sequence is 1 fib(3) = 2 #The 3rd element in the sequence is 2 fib(4) = 3 #The 4th element in the sequence is 3 fib(5) = 5 #The 5th element in the sequence is 5 fib(6) = 8 #The 6th element in the sequence is 8 fib(7) = 13 #The 7th element in the sequence is 13 fib(8) = 21 #The 8th element in the sequence is 21 fib(9) = 34 #The 9th element in the sequence is 34

#Your code here
def fib(n):
    return nth_number

Flat List

Write a function that takes a nested list and flattens it to a list of ints, floats and strings. For example the nested list [1,[2,3[4,5,6]], 7, [8], [9,10]] would become [1,2,3,4,5,6,7,8,9,10] or [1,2[3,4,[5]]] would become [1,2,3,4,5].

#Your code here
def flat_list(L):
    return flattened

Depth vs Breadth First Search

Did you use breadth or depth first recursive calls above? Explain.

#Your answer here.

Summary

Well done! Recursive functions are an advanced topic in Python and you got some good practice tackling classic problems here.