Basic operations on a single-linked table

Basic operations on a single-linked table

  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,int *r){ 89     int length = ListLength(L); 90     if(index < 1 || index > length){ 91         return 0; //failed 92     }else{ 93         int j = 0; 94         while(j<index){ 95             L = L->next; 96             j++; 97         } 98         *r = L->data; 99         return 1;100     }101 }102 void GetPriorElem(LinkList L,int current_elem,int *priorElement){103 /*104     LinkList p = L->next;105     LinkList q;106     if(p == NULL){107         printf("List is Empty!\n");108         exit(1);109     }110     if(p->data == current_elem){111         printf("the current element is first!\n");112         exit(1);113     }114     q = p->next;115     while(q && q->data != current_elem){116         p = q;q = q->next;117     }118     if(q == NULL){119         printf("there is no current in List!\n");120         exit(1);121     }122     else123         *priorElement = p->data;124 */125 /*126 the promise of the following code is that the 127 current_element is not the first element of the128 list and does not consider the case of the list129 for NULL130 */131     LinkList p = L->next; //p point first node132     LinkList q;133     while(p->next){134         q = p->next;135         if(q->data == current_elem){136             *priorElement = p->data;137             break;138         }139         p = q;140     }141     if(p->next == NULL)142         printf("there is no current_element in List\n");143 }144 void GetNextElem(LinkList L,int current_elem,int* next_elem){145     LinkList p = L->next;146     LinkList q;147     if(p == NULL){148         printf("List is Empty!\n");149         exit(1);150     }151     while(p->next){152         q = p->next;153         if(p->data == current_elem){154             *next_elem = q->data;155             return;156         }157         p = q;158     }159     printf("GetNextElement is Failed!\n");160 }161 void HeadCreateList(LinkList* L,int n){162     LinkList s;163     int i;164     int e;165     for(i = 1;i <= n; i++){166         printf("enter %d integer: ",i);167         scanf("%d",&e);168         s = (LinkList)malloc(sizeof(struct Node));169         s->data = e;170         s->next = (*L)->next;171         (*L)->next = s;172     }173     printf("\n");174 }175 void TailCreateList(LinkList* L,int n){176     LinkList tail = *L;177     LinkList s;178     int i;179     int e;180     for(i = 1;i <= n; i++){181         printf("enter %d integer: ",i);182         scanf("%d",&e);183         s = (LinkList)malloc(sizeof(struct Node));184         s->data = e;185         tail->next = s;186         s->next = NULL;187         tail = s;188     }189     printf("\n");190 }191 void ListInsert(LinkList* L,int index,int e){192 /*193 //insert element before index194     LinkList q;195     LinkList p = *L;196     LinkList s;197     int count = 0;198     while(p->next){199         q = p->next;200         count += 1;201         if(count == index){202             s = (LinkList)malloc(sizeof(struct Node));203             s -> data = e;204             p->next = s;205             s->next = q;206             break;207         }208         p = q;209     }210     if(p->next == NULL){211         printf("InsertList Index Error!\n");212     }213 */214 //options215     LinkList p = *L;216     LinkList s;217     int count = 0;218     while(p && count<index-1){219         p = p->next;220         count += 1;221     }222     if(p){223         s = (LinkList)malloc(sizeof(struct Node));224         s->data = e;225         s->next = p->next;226         p->next = s;227     }228     if(p == NULL){229         printf("InsertList Index Error!\n");230     }231 }232 void ListDelete(LinkList *L,int index,int* e){233     LinkList p = *L;234     int count = 0;235     while(p && count < index - 1){236         p = p->next;237         count += 1;238     }239     if(p){240         if(p->next){241             *e = p->next->data;242             p->next = p->next->next;243         }244         else245             printf("DeleteList Index Error\n");246     }247     if(p == NULL)248         printf("DeleteList Index Error\n");249 }250 void DisplayList(LinkList L){251     if(L == NULL){252         printf("List has been destory!\n");253     }else254     {255         LinkList p = L;256         while(p -> next){257             printf("%d ",p->next->data);258             p = p->next;259         }260         printf("\n********displayList executed!\n");261     }262 }263 void main(){264 //    Node L;265 //    LinkList L1 = &L;266 //    InitLinkList(&L1);267 268     LinkList L;269     InitList(&L);270     TailCreateList(&L,4);271     DisplayList(L);272     ClearList(&L);273     ListEmpty(L);274     DisplayList(L);275     DestoryList(&L);276     DisplayList(L);277 278     InitList(&L);279     TailCreateList(&L,5);280     printf("Length of List is: %d\n",ListLength(L));281     DisplayList(L);282 283     int r0;284     if(GetElem(L,5,&r0)){285         printf("getelement index=5 is : %d\n",r0);286     }287     else288         printf("getelement index=5 is Failed\n");289 290     if(GetElem(L,6,&r0)){291         printf("getelement index=6 is : %d\n",r0);292     }293     else294         printf("getelement index=6 is Failed\n");295 296     int r1;297     GetPriorElem(L,3,&r1);298     printf("the result of GetPriorElement(3) is: %d\n",r1);299 300     int r2;301     GetNextElem(L,3,&r2);302     printf("the result of GetNextElement(3) is: %d\n",r2);303     ListInsert(&L,5,999);304     DisplayList(L);305 306     int r3;307     ListDelete(&L,2,&r3);308     DisplayList(L);309     printf("execute ListDelete index=2 is %d\n",r3);310 }