C语言实现链表

C语言实现链表 - c语言程序开发技术文章 - 红黑联盟
http://www.2cto.com/kf/201109/104029.html

C代码 
/* 
 * @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;  
        } 
    } 
}

作者“萧萧易水寒”