Prime Factor

benchmark.sh

#!/bin/bash

TargetNumber=${1:-5712925402340856}

{
  echo "##### Target Number = $TargetNumber"
  echo
  echo -n "##### primeFactor.pl : perl ";perl -E'say $^V'
  time ./primeFactor.pl $TargetNumber
  echo
  echo -n "##### primeFactor.js : nodejs ";node --version
  time ./primeFactor.js $TargetNumber
  echo
  echo -n "##### primeFactor.cxx : clang-600.0.57 -O2"
  g++ -O2 primeFactor.cxx >& /dev/null
  time ./a.out $TargetNumber
} 2>&1 | tee result.txt  

primeFactor.cxx

#include <iostream>
#include <vector>
#include <cstdlib>

using namespace std;

int main( int argc, char* argv[] )
{

  unsigned long value = 5712925402340856ul;
  if( argc > 1  )
    value = atol( argv[1] );
  unsigned long denom = 2;
  vector<unsigned long> primeFactors;

  cout << "Target number = " << value << endl;

  while( denom <= value )
  {
    if( value % denom == 0 )
    {
      primeFactors.push_back( denom );
      value /= denom;
    }else{
      denom += denom>2 ? 2 : 1;
      if( denom*denom > value )
        denom = value;
    }
  }

  for( auto factor : primeFactors )
    cout<<factor<<" * ";
  cout<<endl;
  return 0;
}

primeFactor.js

#!/usr/bin/env node

var num = 5712925402340856;
if( process.argv.length > 2 ) {
  num=process.argv[2];
}
var loopStartNum = 2;
var condition = true;
var prime = [];

while(condition){
  if (num%loopStartNum == 0) {
    num = num/loopStartNum;
    prime.push(loopStartNum);
  } else {
    loopStartNum += loopStartNum>2 ? 2:1;
    if(num == loopStartNum || loopStartNum*loopStartNum > num){
      prime.push(num);
      condition = false;
    }
  }
}
console.log(num);
console.log(prime);

primeFactor.pl

#!/usr/bin/env perl
use strict;
use warnings;
my $v = shift || 29387422028002;
my $i=2;
my @o = ();
while($i<=$v){
    if($v%$i==0){
        push @o,$i;
        $v/=$i;
    }else{
        $i += $i>2 ? 2 : 1;
        $i=$v if $i*$i>$v;
    }
}
print join " x ",@o;
print "\n";

result.txt

##### Target Number = 5712925402340856

##### primeFactor.pl : perl v5.18.2
2 x 2 x 2 x 3 x 3 x 3 x 3 x 3 x 3 x 7 x 241 x 24097 x 24097

real	0m0.016s
user	0m0.009s
sys	0m0.004s

##### primeFactor.js : nodejs v0.12.2
1
[ 2, 2, 2, 3, 3, 3, 3, 3, 3, 7, 241, 24097, 24097, 1 ]

real	0m0.068s
user	0m0.053s
sys	0m0.014s

##### primeFactor.cxx : clang-600.0.57 -O2Target number = 5712925402340856
2 * 2 * 2 * 3 * 3 * 3 * 3 * 3 * 3 * 7 * 241 * 24097 * 24097 * 

real	0m0.004s
user	0m0.001s
sys	0m0.002s