1 * 栈基本操作
2 * 08/25/2010
3 * 参考自严蔚敏等《数据结构(C语言版)》清华大学出版社
4 */
5 #include <iostream>
6 #include <stdlib.h>
7 #include <assert.h>
8 using namespace std;
9
10 // constant definition
11 static const int STACK_INIT_SIZE = 10; // the size of initial
12 static const int STACK_INCREMENT = 10; // the size of each increase
13
14 // describe the stack
15 typedef struct _STACK{
16 int *bottom;
17 int *top;
18 int size;
19 }STACK, *PSTACK;
20
21 // construct an empty stack
22 void stack_init(STACK &stack)
23 {
24 stack.bottom = (int *) malloc(STACK_INIT_SIZE * sizeof(int));
25 assert(stack.bottom != NULL);
26 stack.top = stack.bottom;
27 stack.size = STACK_INIT_SIZE;
28 }
29
30 // push an element in the stack as the new top
31 void stack_push(STACK &stack, int element)
32 {
33 if((stack.top - stack.bottom) >= stack.size)
34 {
35 // stack is full, allocate more memory
36 stack.bottom = (int *) realloc(stack.bottom, (STACK_INIT_SIZE +
37 STACK_INCREMENT) * sizeof(int));
38 assert(stack.bottom != NULL);
39 stack.top = stack.bottom + stack.size;
40 stack.size += STACK_INCREMENT;
41 }
42
43 *stack.top++ = element;
44 cout << "push " << element << endl;
45 }
46
47 // pop the top element in stack if the stack is not empty
48 void stack_pop(STACK &stack, int &element)
49 {
50 if(stack.top == stack.bottom)
51 {
52 // stack is empty, can not pop stack
53 cout << "ERROR - pop: stack is empty" << endl;
54 return ;
55 }
56
57 element = *(--stack.top);
58 cout << "pop " << element << endl;
59 }
60 // get the top element if stack is not empty
61 void stack_top(const STACK stack, int &element)
62 {
63 if(stack.top == stack.bottom)
64 {
65 cout << "ERROR - top: stack is empty" << endl;
66 element = -1;
67 return;
68 }
69
70 element = *(stack.top - 1);
71 cout << "top " << element << endl;
72 }
73
74 // retrieve the number of elements in stack
75 int stack_length(const STACK stack)
76 {
77 return (int)(stack.top - stack.bottom);
78 }
79
80 // determine whether the stack is empty
81 bool stack_is_empty(const STACK stack)
82 {
83 return (stack.top - stack.bottom) ? false : true;
84 }
85 // destroy the stack and the stack is not exist in memory any more
86 void stack_destroy(STACK &stack)
87 {
88 if(stack.bottom) free(stack.bottom);
89 stack.bottom = stack.top = NULL;
90 cout << "destroy ok" << endl;
91 }
92
93 // clear all elements in stack
94 void stack_clear(STACK &stack)
95 {
96 stack.top = stack.bottom;
97 }
98
99 // traverse the stack and print all elements from top to bottom
100 void stack_print(const STACK stack)
101 { if(stack_is_empty(stack))
102 {
103 cout << "stack is empty" << endl;
104 return ;
105 }
106 cout << "(top) ";
107 int *p = stack.top;
108 while(p != stack.bottom)
109 {
110 cout << *(--p) << " ";
111 }
112 cout << *p << " (bottom)" << endl;
113 }
114 // start from here
115 int main()
116 {
117 STACK stack;
118 stack_init(stack);
119
120 int i, j;
121 for(i=0; i<15; i++)
122 stack_push(stack, i);
123 stack_print(stack);
124 cout << "length " << stack_length(stack) << endl;
125 for(j=0; j<16; j++)
126 stack_pop(stack, i);
127 stack_print(stack);
128
129 if(stack_is_empty(stack)) cout << "stack is empty" << endl;
130 else cout << "stack is not empty" << endl;
131
132 stack_clear(stack);
133 stack_destroy(stack);
134
135 system("PAUSE");
136 return 0;
137 }
