# Python Interpreters Benchmarksx64 ArchLinux : AMD® Ryzen 7 4700U®

## performance measurements

Each table row shows performance measurements for this Pyston program with a particular command-line input value N.

N  CPU secs Elapsed secs Memory KB Code B ≈ CPU Load
104.400.6213,3681069  93% 92% 92% 90% 87% 92% 90% 94%

Read the ↓ make, command line, and program output logs to see how this program was run.

Read fannkuch-redux benchmark to see what this program should do.

## fannkuch-redux Pyston #4 program source code

```# The Computer Language Benchmarks Game
# http://benchmarksgame.alioth.debian.org/
#
# contributed by Joerg Baumann
# many thanks to Oleg Mazurov for his helpful description

from sys import argv
from math import factorial
from multiprocessing import cpu_count, Pool
from itertools import islice, starmap

def permutations(n, start, size):
p = bytearray(range(n))
count = bytearray(n)

remainder = start
for v in range(n - 1, 0, -1):
count[v], remainder = divmod(remainder, factorial(v))
for _ in range(count[v]):
p[:v], p[v] = p[1:v + 1], p

assert(count == 0)
assert(size < 2 or (size % 2 == 0))

if size < 2:
yield p[:]
else:
rotation_swaps = [None] * n
for i in range(1, n):
r = list(range(n))
for v in range(1, i + 1):
r[:v], r[v] = r[1:v + 1], r
swaps = []
for dst, src in enumerate(r):
if dst != src:
swaps.append((dst, src))
rotation_swaps[i] = tuple(swaps)

while True:
yield p[:]
p, p = p, p
yield p[:]
i = 2
while count[i] >= i:
count[i] = 0
i += 1
else:
count[i] += 1
t = p[:]
for dst, src in rotation_swaps[i]:
p[dst] = t[src]

def alternating_flips_generator(n, start, size):
maximum_flips = 0
alternating_factor = 1
for permutation in islice(permutations(n, start, size), size):
first = permutation
if first:
flips_count = 1
while True:
permutation[:first + 1] = permutation[first::-1]
first = permutation
if not first: break
flips_count += 1
if maximum_flips < flips_count:
maximum_flips = flips_count
yield flips_count * alternating_factor
else:
yield 0
alternating_factor = -alternating_factor
yield maximum_flips

def task(n, start, size):
alternating_flips = alternating_flips_generator(n, start, size)
return sum(islice(alternating_flips, size)), next(alternating_flips)

def fannkuch(n):
if n < 0:
for data in islice(permutations(-n, 0, factorial(-n)), factorial(-n)):
print(''.join(map(lambda n: str(n + 1), data)))
else:
assert(n > 0)

task_count = cpu_count()
total = factorial(n)
task_size = (total + task_count - 1) // task_count

if task_size < 20000:
task_size = total
task_count = 1

assert(task_size % 2 == 0)

task_args = [(n, i * task_size, task_size) for i in range(task_count)]

if task_count > 1:
with Pool() as pool:
checksums, maximums = zip(*pool.starmap(task, task_args))
else:
checksums, maximums = zip(*starmap(task, task_args))

checksum, maximum = sum(checksums), max(maximums)
print("{0}\nPfannkuchen({1}) = {2}".format(checksum, n, maximum))

if __name__ == "__main__":
fannkuch(int(argv))
```

### make, command-line, and program output logs

``` Thu, 06 May 2021 21:45:33 GMT

COMMAND LINE:
/usr/bin/pyston fannkuchredux.pyston-4.pyston 10

PROGRAM OUTPUT:
73196
Pfannkuchen(10) = 38
```