Python recursive function counting the user

user_11950775 0
Viewed 20697

The count_users function recursively counts the amount of users that belong to a group in the company system, by going through each of the members of a group and if one of them is a group, recursively calling the function and counting the members. But it has a bug! Can you spot the problem and fix it?

def count_users(group):
    count = 0
    for member in get_members(group):
        count += 1
        if is_group(member):
            count += count_users(member)
    return count
print(count_users("sales")) # Should be 3
print(count_users("engineering")) # Should be 8
print(count_users("everyone")) # Should be 18
recursion python-3.x
6 Answers
def count_users(group):
    count = 0
    for member in get_members(group):
    #count += 1
        if is_group(member):
            count += count_users(member)
        else:
            count+=1
    return count

print(count_users("sales")) # Should be 3
print(count_users("engineering")) # Should be 8
print(count_users("everyone")) # Should be 18
user_134665990

The problem lies in your for loop. Currently you increase your count by 1 for each "member" of the group, even if that member is a group itself. Instead move this line into a new else branch after the if is_group(member), so it will only be increased by either the number of members if member is a group, or 1 if member is not a group.

user_36314060 
def count_users(group):
  count = 0
  for member in get_members(group):
    count += 1
    if is_group(member):
      count += count_users(member)-1
  return count

print(count_users("sales")) # Should be 3
print(count_users("engineering")) # Should be 8
print(count_users("everyone")) # Should be 18
user_132469300

Here's the correct solution :

def count_users(group):
  count = 0
  for member in get_members(group):
    count += 1
    if is_group(member):
      count += count_users(member)-1
 return count

print(count_users("sales")) # Should be 3

print(count_users("engineering")) # Should be 8

print(count_users("everyone")) # Should be 18

user_135605990 
def count_users(group):
  count = 0
  for member in get_members(group):
    #count += 1
    if is_group(member):
      count += count_users(member)
    else:
      count += 1
  return count

print(count_users("sales")) # Should be 3
print(count_users("engineering")) # Should be 8
print(count_users("everyone")) # Should be 18
user_107655650 
def count_users(group):
  count = 0
  for member in get_members(group):
    count += 1
    if is_group(member):
      count += count_users(member)
      count -= 1
  return count

print(count_users("sales")) # Should be 3
print(count_users("engineering")) # Should be 8
print(count_users("everyone")) # Should be 18

count -= 1 means that the one one assumed member that turned out to be a group just needs to be eliminated from the count variable.

user_83032590
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