这是我个人写的一个学生管理系统，这是我仅仅用来练手的代码，要知道链表可是你在面试过程中最大机率会考到的，我是陆续从单向链表入门，然后采用双向链表写的代码！如有BUG，请指正，让我们
共同进步！ 
 1 #include<stdio.h>  2 #include<malloc.h>  3 #include<string.h>  4 struct student  5 {  6      int id;  7      char name[100];  8      int age;  9      int sex; 10      int class_num; 11      struct student *next; 12      struct student *pr; 13 }; 14 typedef struct student link; 15 link *head; 16 int insert() 17 { 18      link *newnode; 19      newnode = (link *)malloc(sizeof(struct student)); 20          link *temp_head = head; 21          printf("请输入学生ID：\n"); 22      scanf("%d",&newnode->id); 23      printf("请输入学生姓名：\n"); 24      scanf("%s",newnode->name); 25      printf("请输入学生年龄:\n"); 26      scanf("%d",&newnode->age); 27      printf("请输入学生性别0(代表男 1代表女):\n"); 28      scanf("%d",&newnode->sex); 29      if((newnode->sex == 0|| newnode->sex == 1) == 0) 30      { 31          printf("input is fail!\n"); 32          scanf("%d",&newnode->sex); 33      } 34       printf("请输入学生的班级号码：\n"); 35       scanf("%d",&newnode->class_num); 36       newnode->next = NULL; 37       newnode->pr = NULL; 38          if(temp_head->next == NULL) 39          {       40           temp_head->next = newnode; 41           newnode->pr = temp_head; 42           newnode->next = NULL; 43           return 0; 44          } 45    int flag = 0; 46    while(temp_head->next != NULL) 47    {     48         if(newnode->id < temp_head->next->id) 49         { 50              newnode->next = temp_head->next; 51              newnode->pr = temp_head; 52              temp_head->next = newnode; 53              newnode->next->pr = newnode; 54              flag = 1; 55              break; 56          }  57         temp_head = temp_head->next; 58     } 59     if(flag == 0) 60       { 61            temp_head->next = newnode; 62        newnode->next = NULL; 63        newnode->pr = temp_head; 64       } 65    return 0; 66 } 67 int input() 68 { 69   char num[100]; 70   scanf("%s",num); 71   if(strcmp(num,"insert") == 0) 72   { 73       return 1; 74   } 75   else if(strcmp(num,"delete") == 0) 76   { 77       return 2; 78   } 79   else if(strcmp(num,"display") == 0) 80   { 81       return 3; 82   } 83   else if(strcmp(num,"exit") == 0) 84   { 85       return 4; 86   } 87   else 88   { 89       return 0; 90   }   91 } 92 int display(int id) 93 { 94     link *temp_head = head; 95     int flag = 0; 96     if(temp_head->next == NULL) 97     { 98        printf("没有输入学生信息：\n"); 99        return 0;100     }101     while(temp_head != NULL)102     {103         if(temp_head->id == id)104         {105            printf("id = %d\n name = %s\n age = %d\n sex = %d\n class_num = %d\n",temp_head->id,temp_head->name,temp_head->age,temp_head->sex,temp_head->class_num);106            flag = 1;107            break;108      }109      temp_head = temp_head->next;110     }111     if(flag == 0)112     {113        printf("查无此人！\n");    114     }115     return 0;116 }117 int delete(int id)118 {119      link *temp_head = head;120      int flag;121      if(temp_head->next == NULL)122      {123             printf("学生内容为空，无法删除\n");124             return 0;125      }126      while(temp_head != NULL)127      {128         if(temp_head->id == id)129           {130                 if(temp_head->next == NULL)131                   {132                       temp_head->pr->next = NULL;133                       flag = 1;134                       break;135                   }136               else137                {138                  temp_head->pr->next = temp_head->next;139                  temp_head->next->pr = temp_head->pr;140                  flag = 1;141                     break;142                 }    143           }144           temp_head = temp_head->next;145           146      }147      if(flag == 1)148      {149          printf("删除成功!\n");150      }151      else152      {153          printf("删除失败!\n");154      }155      return 0;156 }157 int main()158 {159     int pid;160     int id;161     int class_num;162     head = (link *)malloc(sizeof(struct student));163     head->next = NULL;164     head->pr = NULL;165     printf("/****************************\n");166     printf("\t欢迎使用学生管理系统\n");167     printf("\t输入insert添加学生信息\n");168     printf("\t输入delete删除学生信息\n");169     printf("\t输入display查看学生信息\n");170     printf("\t输入exit退出程序\n");171     printf("*************************/\n");172     printf("请输入命令！\n");173     pid = input();174     while(pid != 4)175     {176         switch(pid)177         {178           case 1 :179                     insert();180                 break;181           case 2 :182                 printf("请输入要删除的学生ID：\n");183             scanf("%d",&id);184             delete(id);185                     break;186           case 3 :187                 printf("请输入要显示的学生ID：\n");188             scanf("%d",&id);189             display(id);190                     break;191           case 0 :192                     printf("输入的命令有误，请重新输入：\n");193                 break;194           case 4 :195                     break;196          }197      printf("请输入命令！\n");198      pid = input();199    }200    printf("该程序结束！\n");201     return 0;202 }