C语言实现链表
??? 最近闲暇之际，重新看了一下C语言和数据结构，感觉链表很有意思，按照书上的思路自己写了一个重新，实现单向链表的操作，支持增加，删除，查找，读文件操作。先自己保留着，以后用的时候参考
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/* * @author: lizhenbin * @date: 2011-09-14 * @descrption: list operation */#include <stdio.h>#include <stdlib.h>#include <conio.h>#define NULL 0/* define a link node strut */struct student {long num;struct student *prior; /* define point to the struct */struct student *next;};/* create struct */struct student *create(){struct student *head; /* link head and node point */struct student *p;struct student *q;long x;head = (struct student*)malloc(sizeof(struct student));q = head;head->next = NULL;printf("\nPlease input node numbers to the list: \n");scanf("%ld",&x);while(x!=0) {/* create node */p = (struct student*)malloc(sizeof(struct student));p->num = x;p->next = NULL;q->next = p;p->prior = q;q = p;scanf("%ld",&x);}return head;}/* Output list all datas */void print(struct student *head){struct student *p;p = head->next;printf("\nThe list is: ");if(p==NULL) {printf("\nInput list is NULL!");}while(p!=NULL) {printf("%ld ", p->num);p = p->next;}printf("\n");}/* delete list node */void del(struct student *head){struct student *p;struct student *q;int i;int j=0;printf("Please input delete position: ");scanf("%d", &i);if(i<1) {printf("You input %d error.", i);printf("\nTry again, Input nnum: ");scanf("%d", &i);}p = head;while(j<=i-1 && p!=NULL) {p = p->next;j++;}if(p==NULL){printf("\nThere is no %d in the list.", i);exit(1);}else{/* delete list node */q = p;p->prior->next = p->next;p->next->prior = p->prior;p = p->next;free(q);}}/* insert list node */void insert(struct student *head){struct student *p;struct student *q = head;int i;int j = 0;p = (struct student*)malloc(sizeof(struct student));printf("\nPlease input the student No you want to insert: ");scanf("%ld", &p->num);printf("\nInput the student %d position to insert: ",p->num);scanf("%d", &i);if(i<1) {printf("\nYou input %d error.", i);printf("\nTry again, Input nnum: ");scanf("%d", &i);}while(j<=i-1 && q->next!=NULL) {q = q->next;j++;}if(q->next==NULL && j!=i){p->next = NULL;p->prior = q;q->next = p;}else{q->prior->next = p;p->prior = q->prior;p->next = q;q->prior = q;}}/* search list node position and data */void search(struct student *head){struct student *p;long number, i=1, j=0;printf("\nPlease input the index you want to search: ");scanf("%d", &number);p = head->next;printf("\nThe number in the list position is: ");while(p!=NULL){if(p->num==number){printf("%d\n",i);j = 1;}p = p->next;i++;}if(j==0) {printf("There is no %ld in the list.\n",number);}}/* read data from file input */struct student *filein() {struct student *p1;struct student *p2;struct student *head;int i = 0;FILE *fp;char file[20] = "d:/list/node.txt";printf("\nFileName is: %s\n", file);if((fp=fopen(file, "r"))==NULL){printf("Can not open file: %s", file);exit(0);}p2 = (struct student*)malloc(sizeof(*p1));head = p2;p1 = (struct student*)malloc(sizeof(*p1));while(fread(p1, sizeof(*p1), 1, fp)==1){i++;p2->next = p1;p2 = p1;p1->next = NULL;p1 = (struct student*)malloc(sizeof(*p1));}free(p1);fclose(fp);if(i==0){printf("\nNo recored in %s ", file);}return head;}/* save the list result to file */void savefile(struct student* head){struct student *p1;FILE *fp;char file[20] = "d:/list/node.txt";printf("\nFileName: %s", file);printf("\nPlease wait.../n");if((fp=fopen(file,"w"))==NULL){printf("\nCan not open file: %s", file);exit(0);}p1 = head->next;while(p1!=NULL){fwrite(p1, sizeof(struct student), 1, fp);p1 = p1->next;}fclose(fp);}/* print the operate menu */void showMenu(){printf("|-------------------------------------------------|\n");printf("| Link List Opearte Menu |\n"); printf("|-------------------------------------------------|\n");printf("| 1: Insert |\n");printf("| 2: Delete |\n");printf("| 3: Search |\n");printf("| 4: FileIn |\n"); printf("| 5: Savefile |\n");printf("| 6: Print List |\n");printf("| 7: Print Menu |\n");printf("| 8: Exit |\n");printf("|-------------------------------------------------|\n");}/* main funtion */void main(){int a=0;struct student *la;la = create();/*la = (struct student*)malloc(sizeof(struct student));la->next = NULL;*/while(1){showMenu();scanf("\n%d", &a);switch(a){case 1: insert(la); break;case 2: del(la); break;case 3: search(la); break;case 4: filein(); break;case 5: savefile(la); break;case 6: print(la); break;case 7: showMenu(); break;case 8: exit(1);default: printf("\nInput error,Try again.");break; }}}?