Why i run this code in "Land ho!" Code coach chellenge and it's wrong in case 3???(help me plz)

Question

def timetowait(x):
if x < 20:
return 10
else:
return 20 + timetowait(x-20)
people=int(input())
print(timetowait(people))

#the mission is to calculate the time you come to the other side of the sea . taking people are in front of you as input , Each ride lasts 20 minutes, Including going back and forth, and each ride can carry 20 people

#For example:
Your input:
20
Output:
30

#because you are the 21st person and the first ride carry 20 people (not you) , so you will wait 20 for back and forth,then it takes you 10 minutes to go to other side

Answer 1

TCorn your solution is correct, but throw error (maximum recursion call) for big input: recursive function cannot be called successively more than 999 times (at least on sololearn python execution):

https://code.sololearn.com/cGCKS7CT6wLk/?ref=app

that means 998 times from itself...

so, for input greater than (999*20 == 19 980), you will have error (no output) ^^

simple use of floor (whole) division (//) let you handle arbitrary big numbers:

people = int(input())
print(10+(people//20))

(parenthesis inside expression -- around floor division -- are optional due to operator precedence)

Answer 2

I think the recursion is causing the problem. Why not just use a simple math expression? After 'else' you just want to return 10 plus 20 times the number of times 20 goes into x.