Please tell me how this code works:-

Question

def calc(list):
if len(list)==0:
return 0
else:
return list[0]**2 + calc(list[1:])

list = [1, 3, 4, 2, 5]
x = calc(list)
print(x)

Answer 1

calc([1,3,4,2,5])
1**2 + calc([3,4,2,5])
1**2 + 3**2 + calc([4,2,5])
1**2 + 3**2 + 4**2 + calc([2,5])
1**2 + 3**2 + 4**2 + 2**2 + calc([5])
1**2 + 3**2 + 4**2 + 2**2 + 5**2 + 0
1 + 9 + 16 + 4 + 25 + 0
55

Answer 2

Please take paper and pencil and analyse it yourself step by step. Although the concept of recursion is easy, must be experienced by going into detail a few times. See.... one can explain cricket 1000 hours. It won't enable you to become a good player.

Answer 3

Thanks bro but I want to know how the recursion works here.

Answer 4

Side note: don't use reserved words, like "list", to name variables, functions, or anything else. It can get you side effects which are hard to debug.

Answer 5

Is equal to sum+=x^2 for x in list

Answer 6

Ok

Answer 7

Thanks for the explanation

Answer 8

list= [1,3,4,2,5]

def calc(list):
if len(list)==0:
return 0

else:
return list[0]**2+calc(list[1:])

x=calc(list)
print(x

Answer 9

Results 55