mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-11-27 15:01:08 +00:00
6aaf0a2c77
* maths/number_of_digits.py: Streamline benchmarks ``` num_digits(262144): 6 -- 0.2226011250168085 seconds num_digits_fast(262144): 6 -- 0.13145116699161008 seconds num_digits_faster(262144): 6 -- 0.09273383300751448 seconds num_digits(1125899906842624): 16 -- 0.6056742920191027 seconds num_digits_fast(1125899906842624): 16 -- 0.15698366600554436 seconds num_digits_faster(1125899906842624): 16 -- 0.1027024170034565 seconds num_digits(1267650600228229401496703205376): 31 -- 1.1957934170495719 seconds num_digits_fast(1267650600228229401496703205376): 31 -- 0.15552304196171463 seconds num_digits_faster(1267650600228229401496703205376): 31 -- 0.13062308297958225 seconds ``` * updating DIRECTORY.md * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci * Update number_of_digits.py Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com> Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
90 lines
1.8 KiB
Python
90 lines
1.8 KiB
Python
import math
|
|
from timeit import timeit
|
|
|
|
|
|
def num_digits(n: int) -> int:
|
|
"""
|
|
Find the number of digits in a number.
|
|
|
|
>>> num_digits(12345)
|
|
5
|
|
>>> num_digits(123)
|
|
3
|
|
>>> num_digits(0)
|
|
1
|
|
>>> num_digits(-1)
|
|
1
|
|
>>> num_digits(-123456)
|
|
6
|
|
"""
|
|
digits = 0
|
|
n = abs(n)
|
|
while True:
|
|
n = n // 10
|
|
digits += 1
|
|
if n == 0:
|
|
break
|
|
return digits
|
|
|
|
|
|
def num_digits_fast(n: int) -> int:
|
|
"""
|
|
Find the number of digits in a number.
|
|
abs() is used as logarithm for negative numbers is not defined.
|
|
|
|
>>> num_digits_fast(12345)
|
|
5
|
|
>>> num_digits_fast(123)
|
|
3
|
|
>>> num_digits_fast(0)
|
|
1
|
|
>>> num_digits_fast(-1)
|
|
1
|
|
>>> num_digits_fast(-123456)
|
|
6
|
|
"""
|
|
return 1 if n == 0 else math.floor(math.log(abs(n), 10) + 1)
|
|
|
|
|
|
def num_digits_faster(n: int) -> int:
|
|
"""
|
|
Find the number of digits in a number.
|
|
abs() is used for negative numbers
|
|
|
|
>>> num_digits_faster(12345)
|
|
5
|
|
>>> num_digits_faster(123)
|
|
3
|
|
>>> num_digits_faster(0)
|
|
1
|
|
>>> num_digits_faster(-1)
|
|
1
|
|
>>> num_digits_faster(-123456)
|
|
6
|
|
"""
|
|
return len(str(abs(n)))
|
|
|
|
|
|
def benchmark() -> None:
|
|
"""
|
|
Benchmark multiple functions, with three different length int values.
|
|
"""
|
|
from collections.abc import Callable
|
|
|
|
def benchmark_a_function(func: Callable, value: int) -> None:
|
|
call = f"{func.__name__}({value})"
|
|
timing = timeit(f"__main__.{call}", setup="import __main__")
|
|
print(f"{call}: {func(value)} -- {timing} seconds")
|
|
|
|
for value in (262144, 1125899906842624, 1267650600228229401496703205376):
|
|
for func in (num_digits, num_digits_fast, num_digits_faster):
|
|
benchmark_a_function(func, value)
|
|
print()
|
|
|
|
|
|
if __name__ == "__main__":
|
|
import doctest
|
|
|
|
doctest.testmod()
|
|
benchmark()
|