IntStack(存放int型值，带迭代器) 附模板化实现 p406

1 该栈只用于存在int型数据

  1 #include "../require.h"
  2 #include <iostream>
  3 
  4 using namespace std;
  5 
  6 
  7 class IntStack
  8 {
  9     enum { ssize = 20 };
 10     int stack[ssize];
 11     int top;
 12 
 13 public:
 14     IntStack() : top(0) {}
 15     void push(int i)
 16     {
 17         require(top < ssize, "Too many push()es");
 18         stack[top++] = i; //int型元素，通过赋值运算符，直接存入IntStack栈内部的 int stack[]数组中
 19     }
 20 
 21     int pop()
 22     {
 23         require(top > 0, "Too many pop()s");
 24         return stack[--top];
 25     }
 26 
 27     class iterator;
 28     friend class iterator;
 29     
 30     class iterator
 31     {
 32         IntStack& intStack;
 33         int index;
 34 
 35     public:
 36         
 37         iterator(IntStack& is) : intStack(is), index(0) {}
 38 
 39         iterator(IntStack& is, bool) : intStack(is), index(is.top) {}
 40 
 41         // 返回迭代器当前位置的元素
 42         int current() const
 43         {
 44             return intStack.stack[index];
 45         }
 46         
 47         // ++i
 48         int operator++()
 49         {
 50             require(index < intStack.top, "iterator moved out of range");
 51             return intStack.stack[++index];
 52         }
 53  
 54         // i++
 55         int operator++(int)
 56         {
 57             require(index < intStack.top, "iterator moved out of range");
 58             return intStack.stack[index++];
 59         }
 60 
 61         // i += 2;
 62         iterator& operator+=(int amount)
 63         {
 64             require(index + amount < intStack.top, "IntStack::iterator::operator+=() tried to moved out of bounds");
 65             index += amount;
 66             return *this;
 67         }
 68 
 69         bool operator==(const iterator& rv) const
 70         {
 71             return index == rv.index;
 72         }
 73 
 74         bool operator!=(const iterator& rv) const
 75         {
 76             return index != rv.index;
 77         }
 78 
 79         friend ostream& operator<<(ostream& os, const iterator& it);
 80     };
 81 
 82     iterator begin()
 83     {
 84         return iterator(*this);
 85     }
 86 
 87     iterator end()
 88     {
 89         return iterator(*this, true);
 90     }
 91 };
 92 
 93 // 重载 << 运算符  -- 全局的
 94 ostream& operator<<(ostream& os, const IntStack::iterator& it)
 95 {
 96     return os << it.current();
 97 }
 98 
 99 
100 
101 int main()
102 {
103     IntStack stack;
104     for (int i = 0; i < 15; i++)
105     {
106         stack.push(i*3);
107     }
108 
109     //----------------------
110     cout << "Traverse the whole IntStack" << endl;
111     
112     IntStack::iterator it = stack.begin();
113     int n=0;
114     while (it != stack.end())
115     {
116         cout << n++ << ": " << it++ << endl;
117     }
118 
119 
120     //----------------------------------
121     cout << "Traverse a portion of the IntStack" << endl;
122 
123 
124     IntStack::iterator start = stack.begin(), end2 = stack.end();
125     start += 2; 
126     end2 += 5; //在此，程序退出
127 
128     cout << "start = " << start << endl;
129     cout << "end = " << end2 << endl;
130 
131     while (start != end2)
132     {
133         cout << start++ << endl;
134     }
135 
136     return 0;
137 };

 

 运行结果：

 

 

----------------------------------------

附模板化实现(cp406)：

容器中放的是值对象，通过重载后的=运算符完成对象数据成员的拷贝（只做了这一层，算是浅拷贝）

StackTemplate.h

 1 #ifndef STACKTEMPLATE_H
 2 #define STACKTEMPLATE_H
 3 
 4 template<class T>
 5 class StackTemplate
 6 {
 7     enum { ssize = 10 };
 8 
 9     T stack[ssize];
10     int top;
11 
12 public:
13     StackTemplate() : top(0) {}
14     
15     void push(const T& i) 
16     { 
17         stack[top++] = i; 
18     }
19 
20     T pop() 
21     { 
22         return stack[--top]; 
23     }
24 
25     int size() 
26     { 
27         return top; 
28     }
29 };
30 #endif

 

 

测试文件

 1 #include "fibonacci.h"
 2 #include "StackTemplate.h"
 3 #include <iostream>
 4 #include <fstream>
 5 #include <string>
 6 #include "Book.h"
 7 
 8 using namespace std;
 9 
10 int main()
11 {
12 
13     cout << "---------- StackTemplate<int> ------------------" << endl;
14     StackTemplate<int> intTempl;
15     for (int i = 0; i < 5; i++)
16     {
17         intTempl.push(fibonacci(i));
18     }
19     for (int k = 0; k < 5; k++)
20     {
21         cout << intTempl.pop() << endl;
22     }
23 
24     cout << "---------- StackTemplate<string> ------------------" << endl;
25 
26 
27     StackTemplate<string> stringTempl;
28     ifstream in("fibonacci.h");
29     string line;
30 
31     while (getline(in, line))
32         stringTempl.push(line);
33 
34     while (stringTempl.size() > 0)
35         cout << stringTempl.pop() << endl;
36 
37 
38     cout << "---------- StackTemplate<Book> ------------------" << endl;
39     {
40         StackTemplate<Book> books;
41 
42         Book bk1("算法精解", "Kyle Loudon", 56.2);
43         Book bk2("Qt程序设计", "Pulat", 10.2);
44 
45         books.push(bk1);
46         books.push(bk2);
47 
48     }
49 
50     return 0;
51 }

 

 

运行结果：

从运行结果可以看出，Book bk1("算法精解", "Kyle Loudon", 56.2);拷贝给了books.stack[0](地址，0018fc2c)； Book bk2("Qt程序设计", "Pulat", 10.2);拷贝给了books.stack[1](地址，0018fc54)

 

从调用Book类析构函数的顺序上看，bk2 --> bk1 --> books（books.stack[9] --> books.stack[8] ...... --> books.stack[1] --> books.stack[0]）

 

因为push参数是 const T& i使用的是引用（引用传递），所有元素入栈时没有产生新的Book对象。StackTemplate<Book>完全拥有Book对象，所以超出其作用域后，能够自动析构Book对象。

 

posted @ 2015-06-27 17:11  asnjudy  阅读(455)  评论(0)  编辑  收藏  举报