caught speeding - CodingBat

most of you are aware of the 'caught speeding' coding problem on CodingBat. I have tried to solve it as below. i am not quite sure why it did not work there. i have viewed other solutions. and i believe the logic is similar but with some differences in implementation.

"You are driving a little too fast, and a police officer stops you. Write code to compute the result, encoded as an int value: 0=no ticket, 1=small ticket, 2=big ticket. If speed is 60 or less, the result is 0. If speed is between 61 and 80 inclusive, the result is 1. If speed is 81 or more, the result is 2. Unless it is your birthday -- on that day, your speed can be 5 higher in all cases."

my code:

def caught_speeding(speed, is_birthday):
  while not is_birthday:
    speed = range(0,81)
    if speed <= 60:
      return 0
    elif speed > 65 and speed < 80:
      return 1
    else: 
      if speed > 81:
        return 2
  return speed - 5

I've added some comments to your code:

def caught_speeding(speed, is_birthday): # << You are given the speed as a parameter
  while not is_birthday: # << you're using a while loop like an 'if' statement
    speed = range(0,81) # << so no need to generate a speed (and you probably meant to use random rather than range
    if speed <= 60:
      return 0
    elif speed > 65 and speed < 80: # << this logic does not match the question
      return 1
    else: 
      if speed > 81: # << what about when you are going 80 or 81 mph?
        return 2
  return speed - 5 # << and if it's your birthday it means you can add 5 mph to the speeds before you get a larger ticket. You are just subtracting 5

There are multiple issues with the code, but can be fixed without too much work.

1. You are taking the speed as input, then again reassigning
   speed inside the function, which overwrites the integer with a
   range object.
2. Your checking is wrong, you are missing the values from 61
   to 65, hence if any number in this range is given as speed to the
   function, you will be stuck in an infinite loop is is_birthday is
   set to False.
3. When is_birthday is True, you are returning the speed - 5 not the ticket he is going to get.

So, you may try this:

def caught_speeding(speed, is_birthday):
  while not is_birthday:
    if speed <= 60:
      return 0
    elif speed > 60 and speed < 81:
      return 1
    else: 
      if speed > 80:
        return 2
  return caught_speeding(speed - 5, False)

print(caught_speeding(64, False))
# 1
print(caught_speeding(64, True))
# 0

Here I have fixed the first two problems as you would expect, and for the last problem, used recursion. So when is_birthday is True, run as if the actual speed is 5 lower and is_birthday == False.

If you want to learn something new (assuming you don't know already):

def caught_speeding(speed, is_birthday):
    two = lambda x: 2 if x > 80 else one(x)
    one = lambda x: 1 if 60 < x <= 80 else zero(x)
    zero = lambda x: 0 if x <= 60 else two(x)
    return two(speed - 5*is_birthday)

Or,

def caught_speeding(speed, is_birthday):
    d = {0: lambda x: x <= 60, 1: lambda x: 60 < x < 81, 2: lambda x: x > 80}
    for ticket, condition in d.items():
        if condition(speed - 5*is_birthday): return ticket

Or (particular for this case),

def caught_speeding(speed, is_birthday):
    speed = speed - 5*is_birthday
    return [speed <= 60, 60 < speed <= 80, speed > 80].index(True)

Or (particular for this case),

def caught_speeding(speed, is_birthday):
    return min(max(0,(speed - 5*is_birthday-41)//20),2)

Or (particular for this case),

def caught_speeding(speed, is_birthday):
    s = speed-5*is_birthday
    return (s>60)+(s>80)

def caught_speeding(speed, is_birthday):
    # speed 60 or less ---> 0
    # b/t 61 and 80 ---> 1
    # 81+ ---> 2
    # if birthday 5+ in all

    if not is_birthday:
        if speed <= 60:
            return 0
        elif speed > 60 and speed <= 80:
            return 1
        elif speed > 80:
            return 2
        else:
            if speed <= 65:
                return 0
    elif speed > 65 and speed <= 85:
        return 1
    elif speed > 85:
        return 2

This seems easy to understand for me:

def caught_speeding(speed, is_birthday):
               
  speed_adj=0
  
  if is_birthday:
    speed_adj=5
  if speed <=61 + speed_adj:
    return 0
  if speed <=80 + speed_adj:
    return 1
  return 2

my code and it's working fine.

def caught_speeding(speed, is_birthday):

    if (is_birthday == False and speed <= 60):
        return 0
    elif (is_birthday == False and (speed > 60 and speed <= 80)):
        return 1    
    elif (is_birthday == False and speed > 80):
        return 2
    elif (is_birthday == True and speed <= 65):
        return 0
    elif (is_birthday == True and (speed > 65 and speed <= 85)):
        return 1
    elif (is_birthday == True and speed > 85):
        return 2
    else:
        pass