求助：写了个栈的实现及应用。实现中出错。

libinary

找到一个错误：
stq s;
InitStack(s);
因为s是指针，所以必须为s分配内存，InitStack里只为s->base分配了内存，没有为s分配内存，所以有段错误。

sswd

谢谢libinary兄为我看程序(看程序很烦人的）。

今天发现了另外一个可用于栈的教学的程序，google上找的，铁出来，希望对大家有用。

1. 
   
2. #include<stdio.h>
   
3. #include<stdlib.h>
   
4. #define ERROR 0
   
5. #define TRUE 1
   
6. #define FALSE 0
   
7. #define OK 1
   
8. #define EQUAL 1
   
9. #define OVERFLOW -1
   
10. #define STACK_INIT_SIZE 100
    
11. #define STACKINCREMENT 10
    
12. 
    
13. typedef int Status ;
    
14. 
    
15. struct STU{
    
16.   char name[20];
    
17.   char stuno[10];
    
18.   int age;
    
19.   int score;
    
20. };
    
21. typedef struct STU SElemType;
    
22. 
    
23. struct STACK
    
24. {
    
25.   SElemType *base;
    
26.   SElemType *top;
    
27.   int stacksize;
    
28. };
    
29. 
    
30. typedef struct STACK SqStack;
    
31. typedef struct STACK *pSqstack;
    
32. 
    
33. Status InitStack(SqStack  **S);
    
34. Status DestroyStack(SqStack *S);
    
35. Status ClearStack(SqStack *S);
    
36. Status StackEmpty(SqStack S);
    
37. int StackLength(SqStack S);
    
38. Status GetTop(SqStack S,SElemType *e);
    
39. Status Push(SqStack *S,SElemType e);
    
40. Status Pop(SqStack *S,SElemType *e);
    
41. Status StackTraverse(SqStack S,Status (*visit)());
    
42. 
    
43. Status InitStack(SqStack **S)
    
44. {
    
45.   (*S)=(SqStack *) malloc(sizeof(SqStack));
    
46.   (*S)->base=(SElemType *)malloc(STACK_INIT_SIZE *sizeof(SElemType));
    
47.   if(!(*S)->base)exit(OVERFLOW);
    
48.   (*S)->top=(*S)->base;
    
49.   (*S)->stacksize=STACK_INIT_SIZE;
    
50.   return OK;
    
51. }
    
52. 
    
53. Status DestroyStack(SqStack *S)
    
54. {
    
55. free(S->base);
    
56. free(S);
    
57. }
    
58. 
    
59. Status ClearStack(SqStack *S)
    
60. {
    
61.   S->top=S->base;
    
62. }
    
63. 
    
64. Status StackEmpty(SqStack S)
    
65. {
    
66.   if(S.top==S.base) return TRUE;
    
67.   else
    
68.     return FALSE;
    
69. }
    
70. 
    
71. int StackLength(SqStack S)
    
72. {
    
73.   int i;
    
74.   SElemType *p;
    
75.   i=0;
    
76.   p=S.top;
    
77.   while(p!=S.base)
    
78.     {p++;
    
79.      i++;
    
80.     }
    
81. }
    
82. 
    
83. Status GetTop(SqStack S,SElemType *e)
    
84. {
    
85.   if(S.top==S.base) return ERROR;
    
86.   *e=*(S.top-1);
    
87.   return OK;
    
88. }
    
89. 
    
90. Status Push(SqStack *S,SElemType e)
    
91. {
    
92. /*
    
93.   if(S->top - S->base>=S->stacksize)
    
94.    {
    
95. 
    
96.      S->base=(SElemType *) realloc(S->base,
    
97.             (S->stacksize + STACKINCREMENT) * sizeof(SElemType));
    
98.      if(!S->base)exit(OVERFLOW);
    
99.      S->top=S->base+S->stacksize;
    
100.      S->stacksize += STACKINCREMENT;
     
101.    }
     
102.   */
     
103. 
     
104.   *(S->top++)=e;
     
105.   return OK;
     
106. }
     
107. 
     
108. Status Pop(SqStack *S,SElemType *e)
     
109. {
     
110.   if(S->top==S->base) return ERROR;
     
111.   *e=*--S->top;
     
112.   return OK;
     
113. }
     
114. 
     
115. Status StackPrintElem(SElemType * e)
     
116. {
     
117.   printf("%s  %s  %d  %d\n",e->name,e->stuno,e->age,e->score);
     
118. }
     
119. Status StackTraverse(SqStack S,Status (*visit)())
     
120. {
     
121.   while(S.top!=S.base)
     
122.      visit(--S.top);
     
123. }
     
124. 
     
125. main()
     
126. {
     
127.   SElemType e;
     
128.   SqStack *Sa;
     
129. 
     
130.   printf("\n\n-------------------SqStack Demo is running...----------------\n\n");
     
131.   printf("First is Push function.\n");
     
132. 
     
133.   InitStack(&Sa);
     
134. 
     
135.   strcpy(e.name,"stu1");
     
136.   strcpy(e.stuno,"100001");
     
137.   e.age=80;
     
138.   e.score=1000;
     
139. 
     
140.   printf("   Now Stack is Empty.\n");
     
141.   StackTraverse(*Sa,StackPrintElem);
     
142. 
     
143.   Push(Sa,e);
     
144. 
     
145.   printf("   Now Stack has one element.\n");
     
146.   StackTraverse(*Sa,StackPrintElem);
     
147. 
     
148.   strcpy(e.name,"stu3");
     
149.   strcpy(e.stuno,"100002");
     
150.   e.age=80;
     
151.   e.score=1000;
     
152.   Push(Sa,e);
     
153.   printf("   Now Stack has another element.\n");
     
154.   StackTraverse(*Sa,StackPrintElem);
     
155. 
     
156.   printf("   Now Pop Stack,the top elem put into variable e.\n");
     
157.   Pop(Sa,&e);
     
158.   printf("%s\n%s\n%d\n%d\n",e.name,e.stuno,e.age,e.score);
     
159. 
     
160.   printf("   Let's see the left of Stack's elem:\n");
     
161.   StackTraverse(*Sa,StackPrintElem);
     
162. 
     
163.   getchar();
     
164.   printf("\n\n\nWelcom to visit [url]http://zmofun.topcool.net\n\n[/url]");
     
165. }
     

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sswd

终于把栈给整明白了。不过上面这个程序写的好像有些问题，不过可以运行
就是下面这个函数

1. 
   
2. int StackLength(SqStack S)
   
3. {
   
4.   int i;
   
5.   SElemType *p;
   
6.   i=0;
   
7.   p=S.top;
   
8.   while(p!=S.base)
   
9.     {p++;
   
10.      i++;
    
11.     }
    
12. }

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他是从栈顶开始计数的，栈顶应该比栈底大，但是循环体却是q++,不明白

libinary

是写错了吧，而且用S.top - S.base不是挺简单的吗？为什么搞的那么麻烦。