Comparação de desempenho entre linguagens de programação

#include <time.h>
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
 
#if defined(_MSC_VER) || defined(_MSC_EXTENSIONS)
  #define DELTA_EPOCH_IN_MICROSECS  11644473600000000Ui64
#else
  #define DELTA_EPOCH_IN_MICROSECS  11644473600000000ULL
#endif
 
struct timezone 
{
  int  tz_minuteswest; /* minutes W of Greenwich */
  int  tz_dsttime;     /* type of dst correction */
};
 
int gettimeofday(struct timeval *tv, struct timezone *tz)
{
  FILETIME ft;
  unsigned __int64 tmpres = 0;
  static int tzflag = 0;
 
  if (NULL != tv)
  {
    GetSystemTimeAsFileTime(&ft);
 
    tmpres |= ft.dwHighDateTime;
    tmpres <<= 32;
    tmpres |= ft.dwLowDateTime;
 
    tmpres /= 10;  /*convert into microseconds*/
    /*converting file time to unix epoch*/
    tmpres -= DELTA_EPOCH_IN_MICROSECS; 
    tv->tv_sec = (long)(tmpres / 1000000UL);
    tv->tv_usec = (long)(tmpres % 1000000UL);
  }
 
  if (NULL != tz)
  {
    if (!tzflag)
    {
      _tzset();
      tzflag++;
    }
    tz->tz_minuteswest = _timezone / 60;
    tz->tz_dsttime = _daylight;
  }
 
  return 0;
}
 
#define TEST
#ifdef TEST
#endif
 
class Person
{
 
    public:
 
        Person(int count) : _next(NULL), _prev(NULL) { _count = count; }
        int shout(int shout, int nth)
        {
            if (shout < nth) return (shout + 1);
            _prev->_next = _next;
 
            _next->_prev = _prev;
            return 1;
        }
        int count() { return _count; }
        Person* next() { return _next; }
        void next(Person* person) { this->_next = person ; }
        Person* prev() { return _prev; }
        void prev(Person* person) { this->_prev = person; }
    private:
        int _count;
        Person* _next;
        Person* _prev;
};
 
class Chain
{
    public:
        Chain(int size) : _first(NULL)
        {
            Person* current = NULL;
            Person* last = NULL;
            for(int i = 0 ; i < size ; i++)
            {
                current = new Person(i);
                if (_first == NULL) _first = current;
                if (last != NULL)
                {
                    last->next(current);
                    current->prev(last);
                }
                last = current;
            }
            _first->prev(last);
            last->next(_first);
        }
        Person* kill(int nth)
        {
            Person* current = _first;
            int shout = 1;
            while(current->next() != current)
            {
                Person* tmp = current;
                shout = current->shout(shout,nth);
                current = current->next();
                if (shout == 1)
                {
                    delete tmp;
                }
            }
            _first = current;
            return current;
        }
        Person* first() { return _first; }
    private:
        Person* _first;
};
 
int main(int argc, char** argv)
{
    int ITER = 100000;
    Chain* chain;
    struct timeval start, end;
    gettimeofday(&start,NULL);
    for(int i = 0 ; i < ITER ; i++)
    {
        chain = new Chain(40);
        chain->kill(3);
        delete chain;
    }
    gettimeofday(&end,NULL);
    fprintf(stdout,"Time per iteration = %d microsecondsnr", (((end.tv_sec - start.tv_sec) * 1000000) + (end.tv_usec - start.tv_usec)) / ITER);
    //fprintf(stdout,"Last man standing is %dnr", (chain->first()->count() + 1));
    return 0;
}
 
}

package com.dnene.josephus;
 
public class Chain {
 
	private Person first = null;
 
	public Chain(int size) {
		Person last = null;
		Person current = null;
 
		for (int i = 0; i < size; i++) {
			current = new Person(i);
 
			if (first == null)
				first = current;
 
			if (last != null) {
				last.setNext(current);
				current.setPrev(last);
			}
 
			last = current;
		}
 
		first.setPrev(last);
		last.setNext(first);
	}
 
	public Person kill(int nth) {
		Person current = first;
		int shout = 1;
 
		while (current.getNext() != current) {
			shout = current.shout(shout, nth);
			current = current.getNext();
		}
 
		first = current;
 
		return current;
	}
 
	public Person getFirst() {
		return first;
	}
 
	public static void main(String[] args) {
 
		int ITER = 100000;
		long start = System.nanoTime();
 
		for (int i = 0; i < ITER; i++) {
			Chain chain = new Chain(40);
			chain.kill(3);
		}
 
		long end = System.nanoTime();
 
		System.out.println("Time per iteration = " + ((end - start) / (ITER))
				+ " nanoseconds.");
	}
}
 
package com.dnene.josephus;
 
public class Person {
 
	int count;
	private Person prev = null;
	private Person next = null;
 
	public Person(int count) {
		this.count = count;
	}
 
	public int shout(int shout, int deadif) {
		if (shout < deadif)
			return (shout + 1);
 
		this.getPrev().setNext(this.getNext());
		this.getNext().setPrev(this.getPrev());
 
		return 1;
	}
 
	public int getCount() {
		return this.count;
	}
 
	public Person getPrev() {
		return prev;
	}
 
	public void setPrev(Person prev) {
		this.prev = prev;
	}
 
	public Person getNext() {
		return next;
	}
 
	public void setNext(Person next) {
		this.next = next;
	}
}

class Person
    attr_reader :count, :prev, :next
    attr_writer :count, :prev, :next
 
    def initialize(count)
        #puts 'Initializing person : ' + count.to_s()
        @count = count
        @prev = nil
        @next = nil
    end
 
    def shout(shout, deadif)
        if shout < deadif
            return shout + 1
        end
        @prev.next = @next
        @next.prev = @prev
        return 1
    end
end      
 
class Chain
    attr_reader :first
    attr_writer :first
 
    def initialize(size)
        @first = nil
        last = nil
        for i in (1..size)
            current = Person.new(i)
            if @first == nil
                @first = current
            end
            if last != nil
                last.next = current
                current.prev = last
            end
            last = current
        end
        @first.prev = last
        last.next = @first
    end
 
    def kill(nth)
        current = @first
        shout = 1
        while current.next != current
            shout = current.shout(shout,nth)
            current = current.next
        end
        @first = current
        return current
    end
end
 
ITER=100000
start = Time.now
ITER.times { |i|
chain = Chain.new(40)
chain.kill(3)
}
ends = Time.now
puts 'Time per iteration = ' + ((ends - start) * 1000000 / ITER).to_s() + " microseconds"

<?php
class Person
{   
    function __construct($c)
    {   
        $this->count = $c;
    }       
 
    function getPrev()
    {       
        return $this->prev; 
    }           
 
    function setPrev($pr)
    {   
        $this->prev = $pr;
    }   
 
    function getNext()
    {
        return $this->next;
    }
 
    function setNext($nxt)
    {
        $this->next = $nxt;
    }
 
    function shout($shout, $nth)
    {
        if ($shout < $nth)
        {
            return $shout + 1;
        }
        $this->getPrev()->setNext($this->getNext());
        $this->getNext()->setPrev($this->getPrev());
        return 1;
    }
}
 
class Chain
{
    var $first;
 
    function __construct($size)
    {
        for($i = 0; $i < $size ; $i++)
        {
            $current = new Person($i);
            if ($this->first == null) $this->first = $current;
            if ($last != null)
            {
                $last->setNext($current);
                $current->setPrev($last);
            }
            $last = $current;
        }
        $this->first->setPrev($last);
        $last->setNext($this->first);
    }
 
    function kill($nth)
    {
        $current = $this->first;
        $shout = 1;
        while($current->getNext() !== $current)
        {
            $shout =  $current->shout($shout,$nth);
            $current = $current->getNext();
        }
        $this->first = $current;
    }
}
 
$start = microtime(true);
$ITER = 100000;
for($i = 0 ; $i < $ITER ; $i++)
{
    $chain = new Chain(40);
    $chain->kill(3);
}
$end = microtime(true);
printf("Time per iteration = %3.2f microsecondsnr",(($end -  $start) * 100000 / $ITER));
?>