链栈
1 #include<stdio.h>
2 #include<malloc.h>
3 #include<stdlib.h>
4
5 typedef struct Node
6 {
7 int data;
8 struct Node * pNext;
9 }NODE, *PNODE;
10
11 typedef struct Stack
12 {
13 PNODE pTop; //top指针
14 PNODE pBottom; //bottom指针
15 }STACK, *PSTACK;
16
17 void init(PSTACK);
18 void push(PSTACK,int);
19 void traverse(PSTACK);
20 bool is_empty(PSTACK);
21 bool pop(PSTACK,int*);
22 void clear(PSTACK);
23
24 int main()
25 {
26 STACK S; //STACK 等价于struct Stack
27 int val;
28
29 init(&S); //目的是造出一个空栈
30 printf("入栈元素是");
31 push(&S,1); //压栈
32 push(&S,2);
33 push(&S,3);
34 push(&S,4);
35 push(&S,5);
36 traverse(&S); //遍历输出
37
38 if( pop(&S,&val) )
39 {
40 printf("出栈成功，出栈的元素是%d ",val);
41 }
42 else
43 {
44 printf("出栈失败!\n");
45 }
46 traverse(&S); //遍历输出
47
48 clear(&S);
49 traverse(&S);
50 return 0;
51 }
52
53 void init(PSTACK pS)
54 {
55 pS->pTop = (PNODE)malloc(sizeof(NODE));
56 if(NULL == pS->pTop)
57 {
58 printf("动态内存分配失败");
59 exit(-1);
60 }
61 else
62 {
63 pS->pBottom = pS->pTop;
64 pS->pTop->pNext = NULL; //pS->Bottom->pNext = NULL;
65 }
66 }
67
68 void push(PSTACK pS,int val)
69 {
70 PNODE pNew = (PNODE)malloc(sizeof(NODE));
71
72 pNew->data = val;
73 pNew->pNext = pS->pTop; //pS->ptop能改成pS->pBottom
74 pS->pTop = pNew;
75 return;
76 }
77
78 void traverse(PSTACK pS)
79 {
80 PNODE p = pS->pTop;
81
82 while(p != pS->pBottom)
83 {
84 printf("%d ",p->data);
85 p = p->pNext;
86 }
87 printf("\n");
88 return;
89 }
90
91 bool is_empty(PSTACK pS)
92 {
93 if(pS->pTop == pS->pBottom)
94 return true;
95 else
96 return false;
97 }
98
99 bool pop(PSTACK pS,int *pVal)
100 {
101 if( is_empty(pS) )
102 {
103 return false;
104 }
105 else
106 {
107 PNODE r = pS->pTop;
108 *pVal = r->data;
109 pS->pTop = r->pNext;
110 free(r);
111 r = NULL;
112 return true;
113 }
114 }
115
116 void clear(PSTACK pS)
117 {
118 if( is_empty(pS) )
119 {
120 return;
121 }
122 else
123 {
124 PNODE p = pS->pTop;
125 PNODE q = NULL;
126
127 while(p != pS->pBottom)
128 {
129 q = p->pNext;
130 free(p);
131 p = q;
132 }
133 pS->pTop = pS->pBottom;
134 }
135 return;
136 }
