I implemented happy_number function:
_happy_set = { '1' }
_unhappy_set = set()
def happy_number(n):
"""
Check if a number is a happy number
https://en.wikipedia.org/wiki/Happy_number
"""
def create_current(n):
current_array = sorted([value for value in str(n) if value != '0'])
return (current_array, ''.join(current_array))
global _happy_set
global _unhappy_set
current_run = set()
current_array, \
current_string = create_current(n)
if current_string in _happy_set:
return True
if current_string in _unhappy_set:
return False
while True:
current_run.add(current_string)
current_array, \
current_string = create_current(sum([int(value) ** 2
for value in
current_string]))
if current_string in current_run | _unhappy_set:
_unhappy_set |= current_run
return False
if current_string in _happy_set:
_happy_set |= current_run
return True
Besides it need some documentation: is it a good implementation? Or
are there things I should do differently?
To decide for the values from 1 to 1E8 if it is happy or not, takes
280 seconds. Not to bad I think. Also not very good.
--
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof
--
https://mail.python.org/mailman/listinfo/python-list
