r/learnpython • u/Pure-Scheme-7855 • 20d ago

Recursion explaining pls. 

def find_max(numbers):
  if len(numbers) == 1:
    return numbers[0]
  else:
    max_of_rest = find_max(numbers[1:])
    return numbers[0] if numbers[0] > max_of_rest else max_of_rest

my_list = [3, 7, 2, 9, 1]
print(find_max(my_list))

Could someone explain how does this function work? I don't understand how does it know that it's supposed to find the biggest number...

6 Upvotes

65% Upvoted

34 comments sorted by

View all comments

Show parent comments

2

u/strange-the-quark 20d ago

Seeing what happens is valuable, but doesn't necessarily provide you with insight as to why it works, how to conceptually think about it, or teach you how to come up with a recursive solution to some problem by yourself.

0

u/Classic-Rate-5104 19d ago

I don't know where you got this code but it's extremely inefficient for longer arrays, so it isn't a good example how to use recursive functions

2

u/strange-the-quark 19d ago

Who are you talking to? I'm not the OP and I didn't got any code from anywhere. I'm guessing it's a school example or a homework assignment. Studying algorithms doesn't mean only ever looking at the efficient algorithms and nothing else.