【线性表】动态分配空间的实现
实现了一个简易的动态分配内存的线性表结构，实现了插入、删除、重载赋值运算符、拷贝构造函数（有bug，编译不过去）
1
2 #ifndef NULL 3 #define NULL 0
4 #endif
5
6 template<class T>
7 class CSQList 8 { 9 public: 10 CSQList(); //构造函数
11 CSQList(const CSQList& sqList); //拷贝构造函数
12 CSQList& operator=(const CSQList& sqList); //重载赋值运算符
13 T* InitSQList(); //初始化线性表
14 T* IncreaseSQList(); //再次为线性表分配内存
15 virtual ~CSQList(); //析构函数
16 inline unsigned int Capacity() const; //获得最大容量
17 inline unsigned int Size() const; //当前元素个数
18 bool Insert(unsigned int pos, T& element); //在第pos个位置插入元素
19 T Delete(unsigned int pos); //删除指定位置的元素，返回删除的元素
20 unsigned int Clear(); //清楚所有元素(并非释放内存)
21
22 protected: 23 T* m_pSQList; 24 const unsigned int m_ncInitLength; //初始可以放的元素个数
25 const unsigned int m_ncIncreaseLength; //增长大小
26 unsigned int m_nCapacity; //当前线性表总可以放的元素个数
27 unsigned int m_nSize; //当前线性表中实际元素个数
28 }; 29
30 template<class T>
31 T CSQList<T>::Delete( unsigned int pos ) 32 { 33 if (pos > m_nSize - 1) 34 { 35 return T(0); //这里是一个潜在问题, potential problem
36 } 37
38 T temp = m_pSQList[pos]; 39
40 //当删除的元素为最后一个元素时，循环条件不成立，直接更改m_nSize的值即可;
41 for (unsigned int index = pos; index < m_nSize - 1; ++ index) 42 { 43 m_pSQList[index] = m_pSQList[index + 1]; 44 } 45
46 -- m_nSize; 47
48 return temp; 49 } 50
51
52 template<class T>
53 CSQList<T>::CSQList() : m_pSQList(NULL), m_ncInitLength(20), m_ncIncreaseLength(10), m_nCapacity(0), m_nSize(0){} 54
55
56 template<class T>
57 T* CSQList<T>::InitSQList() 58 { 59 if (NULL != m_pSQList) 60 { 61 return m_pSQList; 62 } 63
64 m_pSQList = (T*)(malloc(m_ncInitLength * sizeof(T))); 65 if (NULL == m_pSQList) 66 { 67 m_nCapacity = 0; 68 } 69 else
70 { 71 m_nCapacity = m_ncInitLength; 72 } 73
74 return m_pSQList; 75 } 76
77 template<class T>
78 T* CSQList<T>::IncreaseSQList() 79 { 80 if (NULL == m_pSQList) 81 { 82 return NULL; 83 } 84
85 m_pSQList = (T*)realloc(m_pSQList, (m_ncIncreaseLength + m_nCapacity) * sizeof(T)); 86
87 m_nCapacity += (NULL == m_pSQList? 0 : m_ncIncreaseLength); 88
89 return m_pSQList; 90 } 91
92 template<class T>
93 CSQList<T>::~CSQList() 94 { 95 if (NULL != m_pSQList) 96 { 97 free(m_pSQList); 98 m_pSQList = NULL; 99 m_nCapacity = 0; 100 m_nSize = 0; 101 } 102 } 103
104 template<class T>
105 unsigned int CSQList<T>::Capacity() const
106 { 107 return m_nCapacity; 108 } 109
110 template<class T>
111 unsigned int CSQList<T>::Size() const
112 { 113 return m_nSize; 114 } 115
116 template<class T>
117 bool CSQList<T>::Insert(unsigned int pos, T& element) 118 { 119 if (pos < 0 || pos > m_nSize) 120 { 121 return false; 122 } 123
124 //当 当前个数 + 1 大于 最大容量的时候，必须分配空间 125 //如果分配失败，则不能插入元素
126 if (m_nSize + 1 > m_nCapacity) 127 { 128 if (NULL == IncreaseSQList()) 129 { 130 return false; 131 } 132 } 133 //如果插入一个元素 不会超过最大容量，则即使再分配不成功也没有太大问题
134 else if (m_nSize + 1 >= (m_nCapacity * 0.8F)) 135 { 136 IncreaseSQList(); 137 } 138
139 for (unsigned int iBegin = m_nSize; iBegin > pos; -- iBegin) 140 { 141 m_pSQList[iBegin] = m_pSQList[iBegin - 1]; 142 } 143 m_pSQList[pos] = element; 144
145 ++ m_nSize; 146
147 return true; 148 } 149
150 template<class T>
151 unsigned int CSQList<T>::Clear() 152 { 153 unsigned int size = m_nSize; 154 m_nSize = 0; 155
156 return size; 157 } 158
159 template<class T>
160 CSQList<T>::CSQList(const CSQList& sqList) 161 { 162 T* pt = (T*)malloc(sqList.m_nCapacity * sizeof(T)); 163 if (NULL != pt) 164 { 165 if (0 == memcpy_s(pt, sizeof(T) * sqList.Size(), sqList.m_pSQList, sizeof(T) * sqList.Size())) 166 { 167 this->m_pSQList = pt; 168 this->m_nSize = sqList.Size(); 169 this->m_nCapacity = sqList.Capacity(); 170 } 171 } 172 } 173
174 template<class T>
175 CSQList<T>& CSQList<T>::operator =(const CSQList& sqList) 176 { 177 T* pt = (T*)malloc(sqList.m_nCapacity * sizeof(T)); 178 if (NULL != pt) 179 { 180 if (0 == memcpy_s(pt, sizeof(T) * sqList.Size(), sqList.m_pSQList, sizeof(T) * sqList.Size())) 181 { 182 if (this->m_pSQList != NULL) 183 { 184 free(m_pSQList); 185 } 186
187 this->m_pSQList = pt; 188 this->m_nSize = sqList.Size(); 189 this->m_nCapacity = sqList.Capacity(); 190 } 191 } 192
193 return *this; 194 }
在main函数中使用该线性表
1 #include "stdafx.h"
2 #include <iostream>
3 using namespace std; 4 #include "SQList.h"
5
6
7 int _tmain(int argc, _TCHAR* argv[]) 8 { 9 CSQList<int> sqList; 10 sqList.InitSQList(); 11 int num1 = 0x0a; 12 int num2 = 0x01020304; 13
14 sqList.Insert(0, num1); 15 sqList.Insert(1, num2); 16
17 for (int i = 0; i < 20; ++ i) 18 { 19 sqList.Insert(0, num1); 20 } 21
22 int value = sqList.Delete(sqList.Size() - 1); 23
24 CSQList<int> sqList2; // = sqList; //直接用sqList初始化sqList2时编译错误
25 sqList2 = sqList; 26
27 sqList2 = sqList; 28
29 return 0; 30 }
上面第24行如果写为 CSQList<int> sqList2 = sqList; 则编译错误如下：
1>正在编译...
1>SQList.cpp
1>e:\files\datastruct\sqlist\sqlist\sqlist.h(161) : error C2758: “CSQList<T>::m_ncInitLength”: 必须在构造函数基/成员初始值设定项列表中初始化
1> with
1> [
1> T=int
1> ]
1> e:\files\datastruct\sqlist\sqlist\sqlist.h(24) : 参见“CSQList<T>::m_ncInitLength”的声明
1> with
1> [
1> T=int
1> ]
1> e:\files\datastruct\sqlist\sqlist\sqlist.h(161): 编译类 模板 成员函数“CSQList<T>::CSQList(const CSQList<T> &)”时
1> with
1> [
1> T=int
1> ]
1> e:\files\datastruct\sqlist\sqlist\sqlist.cpp(12): 参见对正在编译的类 模板 实例化“CSQList<T>”的引用
1> with
1> [
1> T=int
1> ]
1>e:\files\datastruct\sqlist\sqlist\sqlist.h(161) : error C2758: “CSQList<T>::m_ncIncreaseLength”: 必须在构造函数基/成员初始值设定项列表中初始化
1> with
1> [
1> T=int
1> ]
1> e:\files\datastruct\sqlist\sqlist\sqlist.h(25) : 参见“CSQList<T>::m_ncIncreaseLength”的声明
1> with
1> [
1> T=int
1> ]
1>生成日志保存在“file://e:\Files\DataStruct\SQList\SQList\Debug\BuildLog.htm”
1>SQList - 2 个错误，0 个警告
========== 生成: 0 已成功, 1 已失败, 0 最新, 0 已跳过 ==========
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