雖然之前寫過一個Deque,但是那個屬於C與C++混合的產品,近來在學習C++模板,所以寫了一個C++版,同時第一次嘗試使用Trait技術。
本來已經寫好的文章,發表之後丟失了,好鬱悶,沒心情再寫了,貼貼代碼吧。
這個Trait是用來決定傳遞參數時是使用值傳遞還是引用傳遞
#ifndef _TYPE_TRAITS_H_
#define _TYPE_TRAITS_H_
namespace MyDataStructure
{
template<typename T>
class ParameterTrait
{
private:
template<typename U>
struct __ParaTrait
{
typedef U& ParameterType;
};
template<typename U>
struct __ParaTrait<U*>
{
typedef U ParameterType;
};
template<typename U>
struct __ParaTrait<U&>
{
typedef typename __ParaTrait<U>::ParameterType ParameterType;
};
template<>
struct __ParaTrait<char>
{
typedef char ParameterType;
};
template<>
struct __ParaTrait<unsigned char>
{
typedef unsigned char ParameterType;
};
template<>
struct __ParaTrait<int>
{
typedef int ParameterType;
};
template<>
struct __ParaTrait<unsigned int>
{
typedef unsigned int ParameterType;
};
public:
typedef typename __ParaTrait<T>::ParameterType ParameterType;
};
}
#endif
模板情況下實現的雙端隊列(其實這個只是雙向鏈表,真正的雙端隊列比這個複雜太多了):
#ifndef _DEQUE_H_
#define _DEQUE_H_
#include "..\Utilites\type_traits.h"
namespace MyDataStructure
{
template<typename T>
class BiDirectionNode
{
private:
typedef typename ParameterTrait<T>::ParameterType ParameterType;
public:
BiDirectionNode(const ParameterType value) : value(value),next(nullptr),pre(nullptr) {}
BiDirectionNode(const BiDirectionNode& n)
{
_copy(n);
}
BiDirectionNode& operator = (const BiDirectionNode& n)
{
_copy(n);
return *this;
}
T Value() const { return value; }
T& Value() { return value; }
T* Next() { return next; }
public:
void _copy(const BiDirectionNode& n)
{
value = n.value;
next = n.next;
pre = n.pre;
}
T value;
BiDirectionNode* pre;
BiDirectionNode* next;
};
template<typename T>
class Deque
{
private:
typedef typename BiDirectionNode<T> NodeType;
typedef typename ParameterTrait<T>::ParameterType ParameterType;
public:
Deque() : size(0), head(nullptr),tail(nullptr){}
Deque(const Deque& d){ _copy(d); }
Deque& operator=(const Deque& d){ _destroy(); _copy(d); return *this; }
~Deque(){ _destroy(); }
void Clear() { _destroy(); }
const int Size() { return size; }
bool Empty(){ return size == 0; }
void Push(const ParameterType value)
{
NodeType* n = new NodeType(value);
_push(n);
}
void Insert(const ParameterType value)
{
NodeType* n = new NodeType(value);
_insert(n);
}
bool Pop(T& value)
{
if (size == 0)
return false;
value = head->value;
NodeType* p = head;
if (size == 1)
{
head = tail = nullptr;
}
else
{
head = head->next;
head->pre = nullptr;
}
--size;
delete p;
return true;
}
bool Eject(T& value)
{
if (size == 0)
return false;
value = tail->value;
NodeType* p = tail;
if (size == 1)
{
head = tail = nullptr;
}
else
{
tail = tail->pre;
tail->next = nullptr;
}
--size;
delete p;
return true;
}
private:
void _push( NodeType* n)
{
if (size == 0)
{
head = n;
head->next = nullptr;
head->pre = nullptr;
tail = head;
}
else
{
n->next = head;
n->pre = nullptr;
head->pre = n;
head = n;
}
++size;
}
void _insert( NodeType* n)
{
if (size == 0)
{
head = n;
head->next = nullptr;
head->pre = nullptr;
tail = head;
}
else
{
tail->next = n;
n->pre = tail;
n->next = nullptr;
tail = n;
}
++size;
}
void _copy(const Deque& d)
{
NodeType* node = d.head;
while (node)
{
NodeType* newNode = new NodeType(*node);
_insert(newNode);
node = node->next;
}
}
void _destroy()
{
NodeType* node = head;
while (node)
{
NodeType* p = node->next;
delete node;
node = p;
}
head = tail = nullptr;
size = 0;
}
private:
int size;
NodeType* head;
NodeType* tail;
};
}
#endif
測試代碼:
// Deque.cpp : 定義控制檯應用程序的入口點。
//
#include "stdafx.h"
#include "Deque.h"
#include <iostream>
#include <deque>
using namespace std;
using namespace MyDataStructure;
int _tmain(int argc, _TCHAR* argv[])
{
Deque<int> d;
for (int i = 0; i < 10; ++i)
{
d.Insert(i);
}
Deque<int> d2;
Deque<int> d1 = d2 = d;
int value;
for (int i = 0; i < 10; ++i)
{
if (d1.Eject(value))
cout << value << ' ';
}
cout << endl;
for (int i = 0; i < 10; ++i)
{
if (d2.Eject(value))
cout << value << ' ';
}
cout << endl;
for (int i = 0; i < 10; ++i)
{
if (d.Eject(value))
cout << value << ' ';
}
cout << endl;
cout << d.Size() << endl;
d.Clear();
d1.Clear();
d2.Clear();
return 0;
}
運行結果:
本次寫博客的經驗是:1)以後註釋直接寫在源文件裏,不要到了寫博客的時候才寫在博文裏。2)如果你是寫了一半保存在線上,下次寫完發表時,請先保存一下再發表,不然如果馬上再來修改已經發表的文章的時候,只有之前的一半內容。已被坑死!