Can anyone explain the recursion?

Question

https://code.sololearn.com/c9FDedhV6EnI/?ref=app

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)

When the code sees th5 line and reads the" calc(list[1:])"
The code will see list0 = 1
Then reads the function(calc(list[1:])) again and now is 3 = list0

Answer 1

Take a look at the result of this code 😉
def calc(list):
if len(list)==0:
print('Recursion completed')
return 0
else:
a = list[0]
b = a**2
rec = calc(list[1:])
print(rec,'+',str(a)+'² =',b+rec)
return b+rec

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

Answer 2

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

Calculating list[0] power 2 + (again calling function remaining list with [3, 4,2,5] so now list[0] for new function is 3
Finally returning like

1**2 + ( 3**2 + ( 4**2 + (2**2 + (5**2 +( 0 ) ))))
= 1 + (9 + ( 16 + ( 4 + ( 25 + 0) ) ) ) = 55

Hope it helps..

Answer 3

Jayakrishna🇮🇳 thanks bro it helped alot but why this zero

1**2 + ( 3**2 + ( 4**2 + (2**2 + (5**2 +(||||||| 0 )|||| ))))
= 1 + (9 + ( 16 + ( 4 + ( 25 +||||| 0)||| ) ) ) = 55

Thanks for help

Answer 4

ZIZO Abd alkawy, do not look at my code, look at the result of its work ☺️

Answer 5

Solo your code is hard a bit to me to understand. But anyway thanks for help