顺序栈c++

 1 #include <iostream>
 2 
 3 using namespace std;
 4 
 5 template<class T>
 6 int ChangeSize1D(T *a, const int oldSize, const int newSize )
 7 {
 8     if(newSize<0) throw "new length must be > 0";
 9     T *temp = new T[newSize];
10     int num = min(oldSize, newSize);
11     copy(a, a+num, temp);
12     delete[] a;
13     a = temp;
14     return 0;
15 }
16 
17 template<class T>
18 class MyStack
19 {
20 public:
21     MyStack(int stackcapacity=10);
22     ~MyStack();
23 
24     bool IsEmpty() const;
25     T &Top() const;
26     void Push(const T &item);
27     void Pop();
28 private:
29     T* Stack;
30     int top;
31     int capacity;
32 };
33 
34 template<class T>
35 inline MyStack<T>::MyStack(int stackcapacity):capacity(stackcapacity)
36 {
37     if(capacity<1) throw "capacity must be > 1";
38     Stack = new T[capacity];
39     top = -1;
40 }
41 
42 template<class T>
43 MyStack<T>::~MyStack()
44 {
45     delete[] Stack;
46 }
47 
48 template<class T>
49 inline bool MyStack<T>::IsEmpty() const
50 {
51     return top == -1;
52 }
53 
54 template<class T>
55 inline T& MyStack<T>::Top() const
56 {
57     if(IsEmpty()) throw "stack is empty";
58     return Stack[top];
59 }
60 
61 template<class T>
62 void MyStack<T>::Push(const T& item)
63 {
64     if(top == capacity-1)
65     {
66         ChangeSize1D(Stack, capacity, 2*capacity);
67     }
68     Stack[++top] = item;
69 }
70 
71 template<class T>
72 void MyStack<T>::Pop()
73 {
74     if(IsEmpty()) throw "Stack cannot delete";
75     Stack[top--].~T();
76 }
77 
78 int main()
79 {
80     MyStack<int> st;
81     st.Push(99);
82     st.Push(22);
83     st.Push(13);
84 
85     cout << st.Top() << endl;
86     st.Pop();
87     cout << st.Top() << endl;
88     st.Pop();
89     cout << st.Top() << endl;
90     st.Pop();
91     cout << st.Top() << endl;
92     st.Pop();
93     cout << st.Top() << endl;
94     cout << "Hello world!" << endl;
95     return 0;
96 }