/mobile Handheld Friendly website

 performance measurements

Each table row shows performance measurements for this Python 3 program with a particular command-line input value N.

 N  CPU secs Elapsed secs Memory KB Code B ≈ CPU Load
1023.3223.4240,044797  0% 1% 1% 100%
11273.41273.5340,076797  0% 0% 1% 100%
123,551.603,552.9640,080797  0% 0% 1% 100%

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.

 notes

Python 3.4.0 (default, Mar 17 2014, 08:05:26) [GCC 4.8.1] on linux

 fannkuch-redux Python 3 #2 program source code

# The Computer Language Benchmarks Game
# http://benchmarksgame.alioth.debian.org/
#
# contributed by Jacek Pliszka
# algorithm is based on Java 6 source code by Oleg Mazurov
# source is based on Miroslav Rubanets' C++ submission.
# converted to python by Ian P. Cooke
# converted to generators by Jacek Pliszka

import sys
import math
from multiprocessing import cpu_count, Pool

MAX_PROBLEM_SIZE = 12
MAX_CPU_LIMIT = 4

def PermutationGenerator(length,idx):
    count = [0] * length
    perm =  list(range(length))
        
    for i in range( length - 1, 0, -1 ):
        d, idx  = divmod(idx, math.factorial(i))
        count[i] = d
        perm[:i+1-d],perm[i+1-d:i+1] = perm[d:i+1],perm[:d] #rotate

    yield perm  # first permutation

    while 1:
        perm[0], perm[1] = perm[1], perm[0]   # rotate
        count[1] += 1
        i=1
        while count[i] > i:
            count[i] = 0
            i += 1
            if i >= length:
              break
            count[i] += 1
            perm[:i],perm[i] = perm[1:i+1],perm[0] #rotate
            
        yield perm
    

def task_body( parms ):
  g = PermutationGenerator( parms[0], parms[1] )

  maxflips = 0
  checksum = 0
  for i in range(parms[1], parms[2]):
      data = list(g.next() if sys.version_info[0]<3 else g.__next__() )
      f =  data[0];
      if f > 0:
          flips = 0;        
          while f:
              data[:f+1] = data[f::-1] #reverse
              flips += 1
              f = data[0]
          maxflips = max(maxflips, flips)
          checksum +=  -flips if i%2 else flips

  return maxflips, checksum

usage = """usage fannkuchredux number
number has to be in range [3-12]\n""";

def main():
    if len(sys.argv) < 2:
        print(usage)
        return 1

    length = int(sys.argv[1])
    if length < 3 or length > MAX_PROBLEM_SIZE:
        print(usage)
        return 2

    n = min( cpu_count(), MAX_CPU_LIMIT )
    
    index_max = math.factorial(length)
    index_step = (index_max + n-1) // n

    parms =  [(length,i,i+index_step) for i in range(0,index_max,index_step) ]

    processors = Pool(processes=n)
    res=list(zip(*processors.map(task_body , parms)))

    processors.close()
    processors.join()
    processors.terminate()
    
    print("%d\nPfannkuchen(%d) = %d" % ( sum(res[1]), length, max(res[0])) )
    return 0

if __name__ == "__main__":
  main()

 make, command-line, and program output logs

Tue, 18 Mar 2014 06:38:12 GMT

MAKE:
mv fannkuchredux.python3-2.python3 fannkuchredux.python3-2.py
/usr/local/src/Python-3.4.0/bin/python3.4 -OO -c "from py_compile import compile; compile('fannkuchredux.python3-2.py')"
0.05s to complete and log all make actions

COMMAND LINE:
/usr/local/src/Python-3.4.0/bin/python3.4 fannkuchredux.python3-2.py 12

PROGRAM OUTPUT:
3968050
Pfannkuchen(12) = 65

Revised BSD license

  Home   Conclusions   License   Play