Author: @asottile
In particular I am using day 21's implementation of the IntCode computer. In this version of the IntCode computer, the output instruction receives ASCII integers and prints those characters to the screen.
Here's a sample execution of my FizzBuzz program:
$ python3 ../part1.py IntCode/asottile.txt
1, 2, Fizz, 4, Buzz, Fizz, 7, 8, Fizz, Buzz, 11, Fizz, 13, 14, FizzBuzz, 16, 17, Fizz, 19, Buzz, Fizz, 22, 23, Fizz, Buzz, 26, Fizz, 28, 29, FizzBuzz, 31, 32, Fizz, 34, Buzz, Fizz, 37, 38, Fizz, Buzz, 41, Fizz, 43, 44, FizzBuzz, 46, 47, Fizz, 49, Buzz, Fizz, 52, 53, Fizz, Buzz, 56, Fizz, 58, 59, FizzBuzz, 61, 62, Fizz, 64, Buzz, Fizz, 67, 68, Fizz, Buzz, 71, Fizz, 73, 74, FizzBuzz, 76, 77, Fizz, 79, Buzz, Fizz, 82, 83, Fizz, Buzz, 86, Fizz, 88, 89, FizzBuzz, 91, 92, Fizz, 94, Buzz, Fizz, 97, 98, Fizz, Buzz
> 88414 μsHere's the rough algorithm I used, translated into python
from typing import Tuple
def divmod(n: int, mod: int) -> Tuple[int, int]:
"""implement divison + mod using addition"""
i = 0
sub = -1 * mod
while n >= mod:
n += sub
i += 1
return i, n
def printnum(n: int) -> None:
# build up a divisor, we'll use this to print one digit at a time
tens = 10
while not n < tens:
tens *= 10
tens, _ = divmod(tens, 10)
# print one digit at a time while moving the divisor down
while tens != 0:
tmp1, _ = divmod(n, tens)
_, tmp1 = divmod(tmp1, 10)
tmp1 += ord('0')
print(chr(tmp1), end='')
tens, _ = divmod(tens, 10)
def main() -> int:
start = 1
end = 100
started = 0
while start <= end:
if started:
print(', ', end='')
started = 1
_, remainder_3 = divmod(start, 3)
_, remainder_5 = divmod(start, 5)
both_non_divisible = remainder_3 * remainder_5
if remainder_3 == 0:
print('Fizz', end='')
if remainder_5 == 0:
print('Buzz', end='')
if both_non_divisible:
printnum(start)
start += 1
print('\n', end='')
return 0
if __name__ == '__main__':
exit(main())