keprekar_numbers.py

# source: https://www.hackerrank.com/challenges/kaprekar-numbers/problem
# video: https://youtu.be/UoHhr2dwP6g

def is_mod_kap(num):
    '''Returns True if num is a modified kaprekar number'''
    sq_num_str = str(num ** 2)
    mid = len(sq_num_str) // 2  # floor division
    left = sq_num_str[:mid] or 0
    right = sq_num_str[mid:] or 0

    return num == int(left) + int(right)

def kaprekarNumbers(p, q):
    mod_kap_nums = [str(num) for num in range(p, q + 1) if is_mod_kap(num)]

    if not mod_kap_nums:
        print("INVALID RANGE")
    else:
        print(' '.join(mod_kap_nums))