[数据结构与算法] : 栈的链式实现

头文件

 1 typedef int ElementType;
 2
 3 #ifndef _STACKLI_H_
 4 #define _STACKLI_H_
 5
 6 struct Node;
 7 typedef Node *PtrToNode;
 8 typedef PtrToNode Stack;
 9
10 int IsEmpty(Stack S);
11 Stack CreateStack(void);
12 void DisposeStack(Stack S);
13 void MakeEmpty(Stack S);
14 void Push(ElementType X, Stack S);
15 ElementType Top(Stack S);
16 void Pop(Stack S);
17
18 #endif

源文件

 1 #include "stackli.h"
 2 #include <malloc.h>
 3 #include <stdlib.h>
 4
 5 struct Node
 6 {
 7     ElementType Element;
 8     PtrToNode Next;
 9 };
10
11 int IsEmpty(Stack S)
12 {
13     return S->Next == NULL;
14 }
15
16 // 创建栈的头节点
17 Stack CreateStack(void)
18 {
19     Stack S = (Stack)malloc( sizeof(struct Node) );
20     if( S == NULL )
21     {
22         fprintf(stderr, "%s\n", "Out of space!!!");
23         exit(-1);
24     }
25     S->Next = NULL;
26     return S;
27 }
28
29 // 销毁栈(包括头节点)
30 void DisposeStack(Stack S)
31 {
32     MakeEmpty(S);
33     free(S);
34 }
35
36 // 清空栈就是弹出所有数据
37 void MakeEmpty(Stack S)
38 {
39     if(S == NULL)
40     {
41         fprintf(stderr, "%s\n", "Must use CreateStack first");
42         exit(-1);
43     }
44     else
45         while( !IsEmpty(S) )
46             Pop(S);
47 }
48
49 // 进栈, 插入到头节点之后
50 void Push(ElementType X, Stack S)
51 {
52     PtrToNode TmpCell = (PtrToNode)malloc( sizeof(struct Node) );
53     if(TmpCell == NULL)
54     {
55         fprintf(stderr, "%s\n", "Out of space!!!");
56         exit(-1);
57     }
58     else
59     {
60         TmpCell->Element = X;
61         TmpCell->Next = S->Next;
62         S->Next = TmpCell;
63     }
64 }
65
66 // 返回栈顶元素, 注意S不能为空
67 ElementType Top(Stack S)
68 {
69     if( IsEmpty(S) )
70     {
71         fprintf(stderr, "%s\n", "Empty stack");
72         return -1;
73     }
74     else
75         return S->Next->Element;
76 }
77
78 // 出栈, 删除头节点的后继
79 void Pop(Stack S)
80 {
81     if( IsEmpty(S) )
82     {
83         fprintf(stderr, "%s\n", "Empty stack");
84     }
85     else
86     {
87         PtrToNode P = S->Next;
88         S->Next = P->Next;
89         free(P);
90     }
91 }

测试文件

 1 #include <stdio.h>
 2 #include "stackli.h"
 3
 4 main( )
 5 {
 6     Stack S;
 7     int i;
 8
 9     S = CreateStack( );
10     for( i = 0; i < 10; i++ )
11         Push( i, S );
12
13     while( !IsEmpty( S ) )
14     {
15         printf( "%d ", Top( S ) );
16         Pop( S );
17     }
18
19     DisposeStack( S );
20     return 0;
21 }