C语言项目(一):学生信息管理系统

实现方式：链表

结构定义

 1 typedef struct MyStu MyStudent;
 2 typedef struct node Node;
 3 typedef Node *pNode;
 4
 5 struct MyStu {
 6     char name [20];
 7     int age;
 8     long ID;
 9     double score;
10 };
11
12 struct node {
13     MyStudent student;
14     pNode next;
15 };
16
17 static pNode head = NULL;

基本功能

 1 void InputStudentInformation();
 2
 3 void PrintStudentInformation();
 4
 5 void SaveStudentInformation();
 6
 7 void ReadStudentInformation();
 8
 9 int CountStudentNumber();
10
11 pNode FindStudent();
12
13 pNode FinePrevious(pNode Cur);
14
15 void ModifyStudentInformation();
16
17 void DeleteStudentInformation();
18
19 void Menu();
20
21 void KeyDown();
22
23 void SubMenu();

界面

 1 void Menu() {
 2     printf("********************************************************\n");
 3     printf("==============欢迎使用高校学生成绩管理系统==============\n");
 4     printf("\t=============请选择功能列表==============\n");
 5     printf("\t**************1.录入学生信息**************\n");
 6     printf("\t**************2.输出学生信息**************\n");
 7     printf("\t**************3.统计学生人数**************\n");
 8     printf("\t**************4.查找学生信息**************\n");
 9     printf("\t**************5.修改学生信息**************\n");
10     printf("\t**************6.删除学生信息**************\n");
11     printf("\t**************0.退 出 系 统**************\n");
12     printf("********************************************************\n");
13 }

菜单实现

 1 void KeyDown() {
 2     int choice;
 3     printf("Function to chose (0~6):\n");
 4     scanf("%d", &choice);
 5     switch (choice) {
 6         case 1:
 7             InputStudentInformation();
 8             SaveStudentInformation();
 9             break;
10         case 2:
11             PrintStudentInformation();
12             break;
13         case 3:
14             printf("Total students is %d\n", CountStudentNumber());
15             break;
16         case 4:
17         {
18             pNode Find = FindStudent();
19             if (Find != NULL) {
20                 printf("NUM:%ld\tNAME:%s\tAGE:%d\tSCORE:%lf",
21                        Find->student.ID,
22                        Find->student.name,
23                        Find->student.age,
24                        Find->student.score);
25             }
26             break;
27         }
28         case 5:
29             ModifyStudentInformation();
30             SaveStudentInformation();
31             break;
32         case 6:
33             DeleteStudentInformation();
34             SaveStudentInformation();
35             break;
36         case 0:
37             printf("Welcome to use again!");
38             exit(0);
39         default:
40             printf("Invalid Input!");
41             break;
42     }
43 }

子菜单

 1 void SubMenu() {
 2     printf("********************************************************\n");
 3     printf("==============欢迎使用高校学生成绩管理系统==============\n");
 4     printf("\t=============请选择功能列表==============\n");
 5     printf("\t**************a.修改姓名**************\n");
 6     printf("\t**************b.修改学号**************\n");
 7     printf("\t**************c.修改年龄**************\n");
 8     printf("\t**************d.修改成绩**************\n");
 9     printf("\t**************q.退出系统**************\n");
10     printf("********************************************************\n");
11 }

打印功能

 1 void PrintStudentInformation() {
 2     system("cls");
 3     printf("********************************************************\n");
 4     printf("==============欢迎使用高校学生成绩管理系统==============\n");
 5     printf("********************************************************\n");
 6     pNode tmp = head->next;
 7     while (tmp != NULL) {
 8         printf("NUM:%ld\tNAME:%s\tAGE:%d\tSCORE:%lf\n",
 9                tmp->student.ID,
10                tmp->student.name,
11                tmp->student.age,
12                tmp->student.score);
13         tmp = tmp->next;
14
15     }
16 }

保存功能

 1 void SaveStudentInformation() {
 2     FILE *fp = fopen(PATH, "w+");
 3     if (!fp) {
 4         printf("FAIL");
 5         exit(0);
 6     }
 7     pNode tmp;
 8     tmp = head->next;
 9     while (tmp != NULL) {
10         fwrite(&tmp->student, sizeof(Node), 1, fp);
11         tmp = tmp->next;
12     }
13     fclose(fp);
14     printf("SAVE DONE!");
15 }

读取功能

 1 void ReadStudentInformation() {
 2     FILE *read = fopen(PATH, "r");
 3     if (!read) {
 4         printf("FAIL");
 5         exit(0);
 6     }
 7     MyStudent stu;
 8     while (fread(&stu, sizeof(MyStudent), 1, read)) {
 9         pNode tmp = (pNode)malloc(sizeof(Node));
10         memcpy(tmp, &stu, sizeof(MyStudent));
11         if (head->next == NULL) {
12             head->next = tmp;
13             tmp->next = NULL;
14         }
15         else {
16             pNode tmp_ = head->next;
17             head->next = tmp;
18             tmp->next = tmp_;
19         }
20     }
21     fclose(read);
22     printf("LOAD DONE!");
23 }

计数功能

 1 int CountStudentNumber() {
 2     int cnt = 0;
 3     pNode tmp;
 4     tmp = head->next;
 5     while (tmp != NULL) {
 6         cnt++;
 7         tmp = tmp->next;
 8     }
 9     return cnt;
10 }

增删改查

  1 void InputStudentInformation() {
  2     pNode NewNode = (pNode)malloc(sizeof(Node));
  3     if (head==NULL) {
  4         head = (pNode)malloc(sizeof(Node));
  5         head->next = NewNode;
  6         NewNode->next = NULL;
  7     }
  8     else {
  9         pNode tmp = head->next;
 10         head->next = NewNode;
 11         NewNode->next = tmp;
 12     }
 13     printf("Name:\n");
 14     scanf("%s", NewNode->student.name);
 15     printf("NUM:\n");
 16     scanf("%ld", &NewNode->student.ID);
 17     printf("AGE:\n");
 18     scanf("%d", &NewNode->student.age);
 19     printf("SCORE:\n");
 20     scanf("%lf", &NewNode->student.score);
 21     printf("DONE");
 22 }
 23 pNode FindStudent() {
 24     printf("Enter student ID:\n");
 25     long id_f;
 26     scanf("%ld", &id_f);
 27     pNode tmp;
 28     tmp = head->next;
 29     while (tmp != NULL) {
 30         if (tmp->student.ID == id_f) {
 31             return tmp;
 32         }
 33         tmp = tmp->next;
 34     }
 35     printf("ERROR ID! \n");
 36     return NULL;
 37 }
 38 pNode FinePrevious(pNode Cur) {
 39     pNode tmp;
 40     tmp = head;
 41     while (tmp != NULL) {
 42         if (tmp->next == Cur) {
 43             return tmp;
 44         }
 45         tmp = tmp->next;
 46     }
 47     return NULL;
 48 }
 49 void ModifyStudentInformation() {
 50     pNode Find = FindStudent();
 51     if (Find == NULL) {
 52         printf("ID ERROR!");
 53         return;
 54     }
 55     SubMenu();
 56     char ch;
 57     scanf("%c", &ch);
 58     switch (ch) {
 59         case 'a':
 60             printf("Enter new name:\n");
 61             scanf("%s", Find->student.name);
 62             printf("MODIFY DONE!\n");
 63             break;
 64         case 'b':
 65             printf("Enter new ID:\n");
 66             scanf("%ld", &Find->student.ID);
 67             printf("MODIFY DONE!\n");
 68             break;
 69         case 'c':
 70             printf("Enter new age:\n");
 71             scanf("%d", &Find->student.age);
 72             printf("MODIFY DONE!\n");
 73             break;
 74         case 'd':
 75             printf("Enter new score:\n");
 76             scanf("%lf", &Find->student.score);
 77             printf("MODIFY DONE!\n");
 78             break;
 79         case 'q':
 80             printf("Welcome to using this system again!");
 81             break;
 82         default:
 83             printf("Invalid Input");
 84             break;
 85     }
 86 }
 87 void DeleteStudentInformation() {
 88     pNode Cur = FindStudent();
 89     if (Cur == NULL) {
 90         return;
 91     }
 92     pNode Prev = FinePrevious(Cur);
 93     if (Cur->next == NULL) {
 94         Prev->next = NULL;
 95         free(Cur);
 96     }
 97     else {
 98         pNode tmp = Cur->next;
 99         Cur->next = NULL;
100         Prev->next = tmp;
101         free(Cur);
102     }
103
104 }