栈与队列：栈的链式储存结构

  1 链栈通常用单链表表示，由于栈的主要操作是栈顶插入与删除，显然以链表的头部作为栈顶最方便，而且没必要为了操作方便附加一个头结点
  2 //链式存储结构（将单链表头指针与栈顶合二为一） 
  3 typedef struct StackNode
  4 {
  5     ElemType data;
  6     struct StackNode *next;
  7 }StackNode,*LinkStackPtr;
  8 typedef struct LinkStack
  9 {
 10     LinkStackPtr top;
 11     int count;
 12 }
 13 Status Push(LinkStack *s,ElemType e)
 14 {
 15     LinkStackPtr p = (LinkStackPtr)malloc(sizeof(StackNode));
 16     p->data = e;
 17     p->next = s->top;  //新插入结点的指针域指向栈顶
 18     s->top = p;        //栈顶换成p
 19     s->count++;
 20     return OK;
 21 }
 22 
 23 Status Pop(LinkStack *s,ElemType *e)
 24 {
 25     LinkStackPtr p;
 26     if(StackEmpty(*s))
 27     {
 28         return ERROR;
 29     }
 30     *e = s->top->data;
 31     p = s->top;
 32     s->top = s->top->next;
 33     free(p);
 34     s->count--;
 35     return OK; 
 36 } 
 37 
 38 
 39 可执行代码来自https://blog.csdn.net/sinat_35297665/article/details/79489822
 40 #include <iostream>
 41 
 42 using namespace std;
 43 
 44 typedef struct node{
 45 
 46     int data;
 47 
 48     struct node *next;
 49 
 50 }Node;
 51 
 52  
 53 
 54 typedef struct stack{
 55 
 56     Node *top;            /**书本写法是：加一个bottom，个人感觉没什么用，反而加一个count用于表示节点数会更好*/
 57 
 58     int count;
 59 
 60 }Link_Stack;
 61 
 62  
 63 
 64 /**创建一个空栈*/
 65 
 66 Link_Stack * Creat_stack()
 67 
 68 {
 69 
 70     Link_Stack *p;
 71 
 72     p = new Link_Stack;   /**这一步不要忘！需要给p创建空间*/
 73 
 74     p->count = 0;
 75 
 76     p->top = NULL;
 77 
 78  
 79 
 80     return p;
 81 
 82 }
 83 
 84  
 85 
 86 /**入栈操作：push*/
 87 
 88 Link_Stack * Push_stack(Link_Stack *p,int elem)
 89 
 90 {
 91 
 92     if(NULL == p)
 93 
 94         return NULL;
 95 
 96  
 97 
 98     Node *temp;
 99 
100     temp = new Node;
101 
102     temp->data = elem;
103 
104  
105 
106     temp->next = p->top;   /**注意这里和队列的入队操作不同，next指向不同，为了方便出栈操作*/
107 
108     p->top = temp;
109 
110  
111 
112     p->count += 1;
113 
114  
115 
116     return p;
117 
118 }
119 
120  
121 
122 /**出栈操作：pop*/
123 
124 Link_Stack * Pop_stack(Link_Stack *p)
125 
126 {
127 
128     Node *temp;
129 
130     temp = p->top;
131 
132     if(NULL == p->top)
133 
134     {
135 
136         cout << "The stack is empty." << endl;
137 
138         return p;
139 
140     }
141 
142     else{
143 
144         p->top = p->top->next;    /** temp = temp->next;  千万不能这么写，看看下一步是什么？*/
145 
146         delete temp;
147 
148  
149 
150         p->count -= 1;
151 
152  
153 
154         return p;
155 
156     }
157 
158 }
159 
160  
161 
162 /**栈的遍历：输出栈*/
163 
164 int Show_stack(Link_Stack *p)
165 
166 {
167 
168     Node *temp;
169 
170     temp = p->top;
171 
172  
173 
174     if(NULL == p->top)
175 
176     {
177 
178         cout << "The stack is empty." << endl;
179 
180         return 0;
181 
182     }
183 
184     while(NULL != temp)
185 
186     {
187 
188         cout << temp->data << ‘ ‘;
189 
190         temp = temp->next;
191 
192     }
193 
194     cout << endl;
195 
196  
197 
198     return 0;
199 
200 }
201 
202  
203 
204 int main()
205 
206 {
207 
208     int i = 5;
209 
210     int elem;
211 
212     Link_Stack *p;
213 
214     p = Creat_stack();
215 
216     while(i--)
217 
218     {
219 
220         cin >> elem;
221 
222         Push_stack(p,elem);
223 
224     }
225 
226     cout << "空栈插入5个元素后:" << endl;
227 
228     Show_stack(p);
229 
230  
231 
232     cout << "删除3个元素后:" << endl;
233 
234     for(i = 3;i--;)
235 
236     {
237 
238         Pop_stack(p);
239 
240     }
241 
242     Show_stack(p);
243 
244     cout << "count:" << p->count << endl;
245 
246  
247 
248     cout << "删除2个元素后:" << endl;
249 
250     for(i = 2;i--;)
251 
252     {
253 
254         Pop_stack(p);
255 
256     }
257 
258     Show_stack(p);
259 
260     cout << "count:" << p->count << endl;
261 
262  
263 
264     Push_stack(p,6);
265 
266     cout << "插入元素6后:" << endl;
267 
268     Show_stack(p);
269 
270     cout << "count:" << p->count << endl;
271 
272  
273 
274     return 0;
275 
276 }