顺序栈

 1 #include <iostream>
 2 #include <assert.h>
 3
 4 using namespace std;
 5
 6 template<class T>
 7 class STACK
 8 {
 9 public:
10     STACK(int sz = 100):top(-1), maxLen(sz)
11     {
12         date = new T[sz];
13         assert(date != NULL);
14     }
15     ~STACK(){delete []date;}
16     void Push(const T& a);
17     bool Pop(T& x);
18     bool Top(T& x);
19     bool Empty() const{return top == -1;}
20     bool Full(){return top == maxLen-1;}
21     int Size(){return top+1;}
22     void Clear(){top = -1;}
23     friend ostream& operator << (ostream& os, const STACK<T>& s)
24     {
25         for(int i = 0; i <= s.top; i++)
26             os<<s.date[i]<<" ";
27         return os;
28     }
29 private:
30     T *date;
31     int top;
32     int maxLen;
33     void overflow();
34 };
35
36 template<class T>
37 bool STACK<T>::Top(T& x)
38 {
39     if(Empty())return false;
40     x = date[top];
41     return true;
42 }
43
44 template<class T>
45 void STACK<T>::overflow()
46 {
47     T* newdate = new T[maxLen<<1];
48     if(newdate == NULL)return;
49     for(int i = 0; i <= top; i++)
50         newdate[i] = date[i];
51     maxLen <<= 1;
52     delete []date;
53     date = newdate;
54 }
55
56 template<class T>
57 void STACK<T>::Push(const T& a)
58 {
59     if(Full())overflow();
60     date[++top] = a;
61 }
62
63 template<class T>
64 bool STACK<T>::Pop(T& x)
65 {
66     if(Empty())return false;
67     x = date[top--];
68     return true;
69 }
70
71 int main()
72 {
73     int tmp;
74     STACK<int> s;
75     for(int i = 0; i < 10; i++)
76         s.Push(i);
77     cout << s << endl;
78     s.Pop(tmp);
79     cout << s << endl;
80     s.Top(tmp);
81     cout << tmp << endl;
82     return 0;
83 }