单链表

  1 #include<stdio.h>
  2 #include<stdlib.h>
  3 #include<malloc.h>
  4
  5 typedef int Elemtype;
  6
  7 typedef struct Node{
  8     int data;
  9     struct Node* next;
 10 }Node;
 11
 12 typedef struct Node* LinkList;
 13
 14 void InitLinkList(LinkList *L);
 15 void DestoryList(LinkList* L);
 16 void ClearList(LinkList *L);
 17 void HeadCreateList(LinkList*,int);
 18 void TailCreateList(LinkList*,int);
 19 void DisplayList(LinkList);
 20
 21 //void InitLinkList(Node** L){
 22 //    *L = (LinkList)malloc(sizeof(struct Node));
 23 //    (*L)->next = NULL;
 24 //    //alternation
 25 //}
 26 void InitList(LinkList *L){
 27     *L = (LinkList)malloc(sizeof(struct Node));
 28     (*L)->next = NULL;
 29 }
 30 void DestoryList(LinkList* L){
 31 /*
 32     LinkList p = *L,q;
 33     printf("%d %d\n",p,*L); //p == *L == 7279912
 34     while(p){
 35         q = p->next;
 36         free(p);
 37         p = q;           //last step p = NULL
 38     }
 39     printf("%d %d",p,*L);  //p = 0;*L = 7279912
 40     free(*L);
 41     printf("%d ",*L);      //*L = 7279912
 42 analise the reason for error by the result of "printf"
 43 free(p) is release the block of memory pointed by P,
 44 dose not change pointer p itself.  NULL == 0
 45 */
 46     LinkList q;
 47     while(*L){
 48         q = (*L)->next;
 49         free(*L);
 50         *L = q;
 51     }
 52 }
 53 void ClearList(LinkList *L){
 54     //ClearList(&L);
 55 //    LinkList p = *L;
 56 //    LinkList q;
 57 //
 58 //    TailCreateList(&L,4);
 59 //    DisplayList(L);
 60 //    ClearList(&L);
 61 //    TailCreateList(&L,4);
 62
 63     LinkList p = (*L)->next;
 64     LinkList q;
 65     while(p){
 66         q = p -> next;
 67         free(p);
 68         p = q;
 69     }
 70     (*L)->next = NULL;
 71     printf("LinkList has been clear!\n");
 72 }
 73 void ListEmpty(LinkList L){
 74     if(L->next == NULL)
 75         printf("List empty!\n");
 76     else
 77         printf("Exit Element in List\n");
 78 }
 79 int ListLength(LinkList L){
 80     LinkList p = L->next;
 81     int count = 0;
 82     while(p){
 83         count+=1;
 84         p = p->next;
 85     }
 86     return count;
 87 }
 88 int GetElem(LinkList L,int index){
 89     int count = ListLength(L);
 90     if(index < 1 || index > count+1){
 91         printf("index error!\n");
 92         exit(1);
 93     }
 94     int j = 0;
 95     while(j<index){
 96         L = L->next;
 97         j++;
 98     }
 99     return L->data;
100 }
101 void GetPriorElem(LinkList L,int current_elem,int *priorElement){
102 /*
103     LinkList p = L->next;
104     LinkList q;
105     if(p == NULL){
106         printf("List is Empty!\n");
107         exit(1);
108     }
109     if(p->data == current_elem){
110         printf("the current element is first!\n");
111         exit(1);
112     }
113     q = p->next;
114     while(q && q->data != current_elem){
115         p = q;q = q->next;
116     }
117     if(q == NULL){
118         printf("there is no current in List!\n");
119         exit(1);
120     }
121     else
122         *priorElement = p->data;
123 */
124 /*
125 the promise of the following code is that the
126 current_element is not the first element of the
127 list and does not consider the case of the list
128 for NULL
129 */
130     LinkList p = L->next; //p point first node
131     LinkList q;
132     while(p->next){
133         q = p->next;
134         if(q->data == current_elem){
135             *priorElement = p->data;
136             break;
137         }
138         p = q;
139     }
140     if(p->next == NULL)
141         printf("there is no current_element in List\n");
142 }
143 void GetNextElem(LinkList L,int current_elem,int* next_elem){
144     LinkList p = L->next;
145     LinkList q;
146     if(p == NULL){
147         printf("List is Empty!\n");
148         exit(1);
149     }
150     while(p->next){
151         q = p->next;
152         if(p->data == current_elem){
153             *next_elem = q->data;
154             return;
155         }
156         p = q;
157     }
158     printf("GetNextElement is Failed!\n");
159 }
160 void HeadCreateList(LinkList* L,int n){
161     LinkList s;
162     int i;
163     int e;
164     for(i = 1;i <= n; i++){
165         printf("enter %d integer: ",i);
166         scanf("%d",&e);
167         s = (LinkList)malloc(sizeof(struct Node));
168         s->data = e;
169         s->next = (*L)->next;
170         (*L)->next = s;
171     }
172     printf("\n");
173 }
174 void TailCreateList(LinkList* L,int n){
175     LinkList tail = *L;
176     LinkList s;
177     int i;
178     int e;
179     for(i = 1;i <= n; i++){
180         printf("enter %d integer: ",i);
181         scanf("%d",&e);
182         s = (LinkList)malloc(sizeof(struct Node));
183         s->data = e;
184         tail->next = s;
185         s->next = NULL;
186         tail = s;
187     }
188     printf("\n");
189 }
190 void ListInsert(LinkList* L,int index,int e){
191 /*
192 //insert element before index
193     LinkList q;
194     LinkList p = *L;
195     LinkList s;
196     int count = 0;
197     while(p->next){
198         q = p->next;
199         count += 1;
200         if(count == index){
201             s = (LinkList)malloc(sizeof(struct Node));
202             s -> data = e;
203             p->next = s;
204             s->next = q;
205             break;
206         }
207         p = q;
208     }
209     if(p->next == NULL){
210         printf("InsertList Index Error!\n");
211     }
212 */
213 //options
214     LinkList p = *L;
215     LinkList s;
216     int count = 0;
217     while(p && count<index-1){
218         p = p->next;
219         count += 1;
220     }
221     if(p){
222         s = (LinkList)malloc(sizeof(struct Node));
223         s->data = e;
224         s->next = p->next;
225         p->next = s;
226     }
227     if(p == NULL){
228         printf("InsertList Index Error!\n");
229     }
230 }
231 void ListDelete(LinkList *L,int index,int* e){
232     LinkList p = *L;
233     int count = 0;
234     while(p && count < index - 1){
235         p = p->next;
236         count += 1;
237     }
238     if(p){
239         if(p->next){
240             *e = p->next->data;
241             p->next = p->next->next;
242         }
243         else
244             printf("DeleteList Index Error\n");
245     }
246     if(p == NULL)
247         printf("DeleteList Index Error\n");
248 }
249 void DisplayList(LinkList L){
250     if(L == NULL){
251         printf("List has been destory!");
252         exit(1);
253     }
254     LinkList p = L;
255     while(p -> next){
256         printf("%d ",p->next->data);
257         p = p->next;
258     }
259     printf("\n********displayList executed!\n");
260 }
261 void main(){
262     Node L;
263     LinkList L1 = &L;
264     InitLinkList(&L1);
265
266     LinkList L;
267     InitList(&L);
268     TailCreateList(&L,4);
269     DisplayList(L);
270     ClearList(&L);
271     DisplayList(L);
272     ClearList(&L);
273     DisplayList(L);
274     DestoryList(&L);
275     DisplayList(L);
276
277     ClearList(&L);
278     ListEmpty(L);
279     TailCreateList(&L,5);
280     ListEmpty(L);
281     printf("count of List is: %d\n",ListLength(L));
282     DisplayList(L);
283     printf("getelement index=6 is : %d\n",GetElem(L,6));
284     int r1;
285     GetPriorElem(L,3,&r1);
286     printf("the result of GetPriorElement(3) is: %d\n",r2);
287
288     int r2;
289     GetNextElem(L,3,&r2);
290     printf("the result of GetNextElement(3) is: %d\n",r2);
291     ListInsert(&L,5,999);
292     int r3;
293     ListDelete(&L,5,&r3);
294     printf("execute ListDelete index=5 is %d\n",r3);
295     DisplayList(L);
296 }