alternating between the two ends of the range

Question

the question is - Please write a program which asks the user to type in a number. The program then prints out the positive integers between 1 and the number itself, alternating between the two ends of the range

my code-

num = int(input('Please type in a number:'))
index = 1
while index <= num:
    print(index)
    print(num)
    index += 1
    num -= 1

the program is supposed to this with user input 5-

Please type in a number: 5
1
5
2
4
3

but it instead prints out this

Please type in a number:5
1
5
2
4
3
3

it prints out an extra 3 at the end, how can i fix this?

Answer 1

num = int(input('Please type in a number:'))
index = 1
while index < (num-1):
    print(index)
    print(num)
    index += 1
    num -= 1
print(num)
if index < num:
    print(index)

Having index < (num - 1) prevents index and num from converging. Printing (num) after the while loop takes care of the median number (3 in the case of 5 like you mentioned). If the number is even, the median will be in between 2 numbers, and The if statement at the end allows to print the smaller of those two