学生信息管理系统

半个月前写的程序，因为军训的缘故没写完。当时写的时候懒得一个个函数分别测试，今天编译的时候才发现各种bug，搞了半天还是搞不定，十分烦躁，遂决定先搁着一段时间，等啥时候心情好了再debug。

同时，这个项目了我很大的教训，以后写大项目时一定要分别测试！

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更新1:忙过了开学终于有时间debug了，搞了一上午终于基本上搞定。很多地方懒得考虑错误输出了，所以鲁棒性应该会很弱，但好歹第一次写完一个几百行的程序，还是很开心的。

//head.h#define _CRT_SECURE_NO_WARNINGS #include<stdio.h>#include <string.h> #include<stdlib.h>#define ALL 50      #define LEN sizeof(struct student)typedef struct student                                       {                         // 不要写成typeof    int number;    char name[15];    double Chinese;    double Math;    double English;    double sum;    struct student *next;}Student;Student * head;Student* EDIT(Student* head);Student* DELETE(Student* head);Student* ADD(Student* head);Student* FIND(Student* head);Student* SHOW(Student* head);void COUNT(Student* head);Student* ORDER(Student* head);Student*  INPUT(Student* head);void OUTPUT(Student* head);void INITIAL(void);void PASSWORD(void);void FREE(void);///////////////////////////////////////////////////////////////////////////////////main.cpp#include"head.h"int main(void){    //PASSWORD();    INITIAL();     return 0;} //main函数里定义的变量不是全局变量void PASSWORD(void){    char password[10];//不能使用字符串指针形式，因为那样并没有初始化，第15行会报错    char* right_password = "12345";    printf("Welcome!\n");    printf("Please enter your password:");    scanf("%s", password);//passwordb本身就是地址了，不用再加&    getchar();    int i = 0;    while (strcmp(password, right_password)!=0 && i<3)    {        printf("wrong password!please enter again:");        i++;        scanf("%s", password);        getchar();//处理回车符    }    if (i == 3)//小心 == 写成 =    {        printf("you enter too much wrong password!\n");        exit(0);    }    if (i < 3)    {        printf("succeed!\n");    }}void INITIAL(void){    while (1)    {           printf("please choose what fuction you want to use:\n"        "1.ADD  2.SHOW  3.DELETE    4.EDIT  \n"        "5.FIND 6.COUNT 7.ORDER 8.INPUT\n"        "9.OUTPUT   0.QUIT\n");char choice;scanf("%c", &choice);while (getchar() != '\n') continue;        switch (choice)        {        case'1':            head = ADD(head);            break;        case'3':            head = DELETE(head);            break;        case'4':            head = EDIT(head);            break;        case'2':            head = SHOW(head);            break;        case'5':            head = FIND(head);            break;        case'6':            COUNT(head);            break;        case'7':            head = ORDER(head);            break;        case'8':            head=INPUT(head);            break;        case'9':            OUTPUT(head);            break;        case'0':            FREE();            exit(0);        default:            printf("Invalid enter,please enter again\n");            break;        }    }}Student* ADD(Student* head)  //直接传变量传递的是副本！！ {    while (1)    {        Student* temp = (Student*)malloc(LEN);        printf("please enter sutdents' information,enter 0 to exit!\n");    tag1:        printf("please enter student's number:");        int a = -1;        scanf("%d", &a); //防止退出时改变上一个number的值        while (getchar() != '\n') continue;        if (a)        {            temp->number = a;            if (temp->number < 0)            {                printf("Be serious!\n");                goto tag1;            }        }        else break;        Student *p1 = head, *p2 = head;//为了不改变head        while (p1 != NULL)        {            if (p1->number != temp->number)            {                p1 = p1->next;            }            else            {                printf("this number has already existed,please enter again\n");                goto tag1;            }        }        printf("please enter stduent's name:");        scanf("%s", &(temp->name));        while (getchar() != '\n') continue;        printf("please enter stduent's English grade:");        scanf("%lf", &(temp->English));        while (getchar() != '\n') continue;        printf("please enter stduent's Chinese grade:");        scanf("%lf", &(temp->Chinese));        while (getchar() != '\n') continue;        printf("please enter stduent's Math grade:");        scanf("%lf", &(temp->Math));        while (getchar() != '\n') continue;        temp->sum = temp->English + temp->Chinese + temp->Math;        temp->next = NULL;        if(head==NULL) head = temp;        else        {            while(p2->next != NULL) p2 = p2->next;            p2->next = temp;            temp = NULL;        }    }    return head;}Student* FIND(Student* head){Student* p1=head;printf("please enter student's number you want to search:");int num;scanf("%d", &num);getchar();while (p1->number != num&&p1->next != NULL){    p1 = p1->next;}if (num == p1->number){    printf("number    name      English   Chinese   Math      sum\n");    printf("%-10d%-10s%-10.1f%-10.1f%-10.1f%-10.1f\n", p1->number, p1->name, p1->English, p1->Chinese, p1->Math, p1->sum);}if (num != p1->number) printf("this stduent doesn't exist\n");return head;}Student* EDIT(Student* head){    Student* p1 = head;    printf("please enter student's number you want to edit:");    int num;    scanf("%d", &num);    getchar();    while (p1->number != num&&p1->next != NULL)    {        p1 = p1->next;    }    if (num == p1->number)    {        while (1)        {            printf("please enter which part you want to edit(enter EXIT to exit):");            char part[20];            scanf("%s", part);            getchar();            if (strcmp(part, "name")==0)//strcmp相等返回0            {                printf("What do you want to change into:");                scanf("%s", &p1->name);                getchar();            }            else if(strcmp(part, "Chinese")==0)            {                printf("What do you want to change into:");                scanf("%lf", &p1->Chinese);                getchar();            }            else if(strcmp(part, "English")==0)            {                printf("What do you want to change into:");                scanf("%lf", &p1->English);                getchar();            }            else if (strcmp(part, "Math")==0)            {                printf("What do you want to change into:");                scanf("%lf", &p1->Math);                getchar();            }            else if (strcmp(part, "EXIT")==0)            {                break;            }            else            {                printf("Be serious!\n");                break;            }        }    }    if (num != p1->number) printf("this student doesn't exist\n");    return head;}void COUNT(Student* head){    int count = 1;    Student* p1 = head;    if (p1 == NULL) printf("No stduent\n");    else    {        while (p1->next != NULL)        {            p1 = p1->next;            count++;        }        printf("totally %d stduents\n", count);    }    return ;}Student* DELETE(Student* head){    printf("please enter which student you want to delete:");    int num;    scanf("%d", &num);    getchar();    Student* p1 = head, *p2=NULL;//*p2=NULL是无意义的，然而由于231行如果没进入循环的话242行p2会出现未定义，多以必须提前定义p2    while (p1->number != num && p1->next != NULL)     {        p2 = p1;        p1 = p1->next;    }    if (num == p1->number)    {        if (p1 == head)//记得考虑首节点情况            head = p1->next;        else            p2->next = p1->next;    }    else printf("this stduent doesn't exist\n");    return head;}Student* SHOW(Student* head){    Student* p1 = head;    if (p1 == NULL) printf("no student!\n");    else    {        printf("number    name      English   Chinese   Math      sum\n");        printf("%-10d%-10s%-10.1f%-10.1f%-10.1f%-10.1f\n", p1->number, p1->name, p1->English, p1->Chinese, p1->Math, p1->sum);        while (p1->next != NULL)        {            p1 = p1->next;            printf("%-10d%-10s%-10.1f%-10.1f%-10.1f%-10.1f\n", p1->number, p1->name, p1->English, p1->Chinese, p1->Math, p1->sum);        }    }    return head;}Student* INPUT(Student* head){    printf("please enter the name of file you want to input:");    char name[50];    scanf("%s", name);    getchar();    FILE * fp1;    if ((fp1 = fopen(name, "r+")) == NULL)    {        printf("can't open this file!\n");        return head;    }    int test;    while (1) //如果用feof判断，则会多一次循环    {        Student* temp = (Student*)malloc(LEN);//malloc若放在外面 head会随着temp变化        test=fscanf(fp1, "%d %s %lf %lf %lf %lf", //fscanf不能加格式限定符            &temp->number, temp->name, &temp->English, &temp->Chinese, &temp->Math, &temp->sum);//记住加&        temp->next = NULL;        if (test != 6) break;        Student* p2 = head;        if (head == NULL) head = temp;        else        {            while (p2->next != NULL) p2 = p2->next;            p2->next = temp;        }    }    fclose(fp1);    return head;}void OUTPUT(Student* head){    printf("please enter the name of file you want to output:");    char name[50];    scanf("%s", name);    getchar();    FILE * fp1;    if ((fp1 = fopen(name, "a+")) == NULL)    {        printf("can't open this file!\n");        return;    }    Student* p1 = head;    while (p1!=NULL)//也可用feof判断结尾    {        fprintf(fp1,"%-10d%-10s%-10.1f%-10.1f%-10.1f%-10.1f\n", p1->number, p1->name, p1->English, p1->Chinese, p1->Math, p1->sum);        p1 = p1->next;    }    fclose(fp1);    return ;}Student* ORDER(Student* head){    Student* first = NULL,*new_head=NULL,*min,*p_last=head,*p_now;    while (head != NULL)    {        for (p_now = head, min = head; p_now->next != NULL; p_now = p_now->next)        {            if (p_now->next->number < min->number)            {                p_last = p_now;                min = p_now->next;            }        }        if (first == NULL)        {            first = min;            new_head = first;        }        else        {            first->next = min;            first = first->next;        }        if (min == head)        {            head = head->next;        }        else        {            p_last->next = min->next;        }    }    first-> next = NULL;    head=new_head;    return head;}//按编号排序void FREE(void){    Student* p;    while (head)    {        p = head;        head = head->next;        free(p);    }}