Question

The following is the beginning of an algorithm that accepts an arbitrary collection of numbers from the user (who signifies the end of the input with the value -1)(it's Python):

values = []
print('Enter positive values (-1 to end):')
num = int(input('> '))

(a) Complete the program:

• Collect the data from the user in the list values, using a loop
• Once the loop completes, print the total sum and the average
• Take care to handle the case where the user enters -1 as the first value
  • Print "n/a" for the average in this case

(b) What is the special value (-1) known as, for this type of algorithm?

The following shows the output from a couple of runs of the completed program:

Enter positive values (-1 to end):
> 4
> 12
> 5
> 9
> -1
Total sum: 30
Average: 7.5

Enter positive values (-1 to end):
> -1
Total sum: 0
Average: n/a

Answer 1

values = []

print('Enter positive values (-1 to end):')

num = input('> ')

while num.upper() != '-1' :

values.append(int(num))

num = (input('> '))

print("Total sum: ", sum(values))

if len(values)==0:

print("Average: n/a")

else:

print("Average:", sum(values)/len(values))

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SEE OUTPUT

Files main.py num = main.py saved 1 values = [] 2 print( 'Enter positive values (-1 to end):') 3 input('> ') 4 while num. upper() != '-1' : 5 values.append(int(num)) 6 (input('> ')) 7 Enter positive values (-1 to end): > 4 > 12 > 5 > 9 > -1 Total sum: 30 Average: 7.5 num = 5 8 9 10 11 print("Total sum: ", sum(values)) if len(values )==0: | print("Average: n/a") else: print("Average:", sum(values)/len(values)) 12 13 14

Thanks, PLEASE COMMENT if there is any concern.