Hi, here’s your problem today. This problem was recently asked by LinkedIn:

Given a string, convert it to an integer without using the builtin str function. You are allowed to use ord to convert a character to ASCII code.

Consider all possible cases of an integer. In the case where the string is not a valid integer, return None.

Here’s some starting code:

def convert_to_int(s):
  # Fill this in.

print(convert_to_int('-105') + 1)
# -104