三种传奇语言的速度比较(3)

代码B：

#include <time.h>
#include <stdio.h>
class NoSuchElementException
{};
class IllegalStateException
{};
class List
{
 class Element
 {
 public:
  const int datum;
  Element* next;
  inline Element(const int datum, Element* next)
   :datum(datum),next(next)
  {}
 };

 class Iter
 {
  Element* curr;
 public:
  inline Iter(Element* head)
   :curr(head)
  {}
  inline bool hasNext()const
  {
   return curr != 0;
  }
  inline int next()
  {
   if(curr == 0)
    throw NoSuchElementException();
   const int result = curr->datum;
   curr = curr->next;
   return result;
  }
 };
 Element* head;
 Element* tail;
public:
 inline List()
 {
  head = tail = 0;
 }
 inline bool isEmpty()
 {
  return head == 0;
 }
 void purge()
 {
  Element* curr = head;
  Element* next;
  while(curr!=0)
  {
   next = curr->next;
   delete curr;
   curr = next;
  }

  head = tail = 0;
 }
 inline void append(const int datum)
 {
  if(head == 0)
  {
   head = tail = new Element(datum,0);
  }
  else
  {
   tail->next = new Element(datum, 0);
   tail = tail->next;
  }
 }
 void extract(const int datum)
 {
  if(isEmpty())
   throw NoSuchElementException();
  Element* curr = head;
  Element* pre  = 0;
  while(curr != 0 && curr->datum != datum)
  {
   pre = curr;
   curr = curr->next;
  }
  if(curr == 0)
   throw NoSuchElementException();
  if(curr == head)
  {
   Element* next = head->next;
   delete head;
   head = next;
  }
  else
  {
   pre->next = curr->next;
   delete curr;
  }
  if(curr == tail)
   tail = pre;
 }
 void assign(List* another)
 {
  if(this == another)
   return;
  Iter* iter = another->iterator();
  purge();
  while(iter->hasNext())
  {
   append(iter->next());
  }
  delete iter;
 }
 inline Iter* iterator()
 {
  return new Iter(head);
 }
};

int main()
{
 List from,to; 
 const int length = 100000;
 const int innerLoops = 100;
 for(int i=0;i<length;i++)
  from.append(i);

 clock_t start,end;
 double timeuse;

 for(int i=0;i<3;i++)
 {
  printf("loop %d:\n",i);

  timeuse = 0;
  for(int k=0;k<innerLoops;k++)
  {
   to.purge();
   start = clock();
   for(int j=0;j<length;j++)
    to.append(j);
   end = clock();
   timeuse+=(double)(end-start);
  }
  printf("append: %3.1f M/s\t",length/timeuse*innerLoops/1000);

  timeuse = 0;
  for(int k=0;k<innerLoops;k++)
  {
   to.purge();
   start = clock();
   to.assign(&from);
   end = clock();
   timeuse+=(double)(end-start);
  }
  printf("assign: %3.3f/s\t",innerLoops/timeuse*1000);

  start = clock();
  for(int j=length/2;j<(length/2+1000);j++) 
   to.extract(j);
  end = clock();
  timeuse=(double)(end-start);
  printf("extract: %3.3fk/s\t",1000/timeuse);

  timeuse = 0;
  for(int k=0;k<innerLoops;k++)
  {
   to.assign(&from);
   start = clock();
   to.purge();
   end = clock();
   timeuse+=(double)(end-start);
  }
  printf("purge: %3.3f/s\n",innerLoops/timeuse*1000);
 }
}

编译方式：

cl   /G7  /O2 /arch:SSE2 list.cpp

注：我是p4，所以/G7 /arch:SSE2不是的把它去掉就是了

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