C语言实现——学生管理系统

程序员的必经之路吧，学生管理系统。在制作过程中体会到了编写一个具体可用的软件而要做的工作，无论是编写前的准备，还是编写过程中每个细节的处理，都让我理解了这份工作是个什么样子。程序并不是抬手就来，一个软件要完整，同时还要将每个功能部分区分开，所以在编写之前一定要先规划清楚，这是一项工程。逻辑要严密，编程完全就是对逻辑思维的考验，大大小小的函数、语句都是靠逻辑连接起来的。基础知识要扎实，在我现在这个阶段，经常会遇到为干掉bug而苦思半天，在逻辑上寻觅没有出口，其实只是对用法不了解，上课时认为那种不太常考的东西不用太费心，只要把主要的知识记住就行，但事实上每个知识点都是有用的。

#include<stdio.h>
#include<windows.h>
//#include<conio.h>
//#include<string.h>

struct STUDENT {
char name[10];
int num;
int sex;
double score;
struct STUDENT* next;
}*ListHead;

void menu();
void Import();
void Show();
void Add();
void Search();
void Rank();
void Delete();
void Export();
void Exit();

struct STUDENT* CreatListHead();
void ListInsert(char *name,int num,int sex,double score);
void IfListBlank();
void ExchangeNope(struct STUDENT *p,struct STUDENT *q);
void DeleteNode(struct STUDENT *d);
void WriteList(char *path);
void IfHeadEmpty();

int main(){
// Load();
// clrscr();
// printf("en");
// system("cls");
/* if(ListHead==NULL)
printf("!!!");
else
printf("???");
*/
menu();

return 0;
}

void menu() {
int i;
system("cls");

printf("-----------------------------------------------\n");
printf(" 学生管理系统\n");
printf("-----------------------------------------------\n");
printf(" 1.导入 | 2.显示 | 3.增添 | 4.查找\n");
printf(" 5.排序 | 6.删除 | 7.导出 | 8.退出\n");
printf("-----------------------------------------------\n");
printf("请选择一个选项：");
scanf("%d", &i);
switch(i) {
case 1:Import();break;
case 2:Show();break;
case 3:Add();break;
case 4:Search();break;
case 5:Rank();break;
case 6:Delete();break;
case 7:Export();break;
case 8:Exit();break;
case 9:IfListBlank();break;
default:menu();
}
}

//导入文件---------------------------------------------------------------------------------
void Import(){
ListHead = CreatListHead();
FILE *fp;
char buf[30];
char *iname;
int inum=0;
int isex=0;
double iscore=0;
int i = 0;
char *line;
fp=fopen("students.txt","r");
if(fp==NULL)
{
printf("import failed!&& creat a new file,any key return\n");
ListHead = CreatListHead();
fflush(stdin);
getchar();
menu();
}else{
while(!feof(fp))
{
fgets(buf,30,fp);
line = strtok(buf," \t\r\n");
while(line != NULL)
{
switch(i){
case 0: iname=line; break;
case 1: inum=atoi(line); break;
case 2: isex=atoi(line); break;
case 3: iscore=atof(line); break;
default: break;
}
i++;
// printf("%s %d %d %f\n",iname,inum,isex,iscore);
// ListInsert(iname,inum,isex,iscore);
line = strtok(NULL," \t\r\n");
}
i=0;
// printf("%-10s%-5d %d %4.1f\n",iname,inum,isex,iscore);
ListInsert(iname,inum,isex,iscore);
}
fclose(fp);
}

printf("import successful! anykey to return\n");
fflush(stdin);
getchar();
menu();
}

//显示功能---------------------------------------------------------------------------------
void S
4000
how(){
IfHeadEmpty();
struct STUDENT *prep,*p;
prep = ListHead;
p = ListHead->next;
while(p)
{
prep = p;
p =p->next;
if(prep->sex)
{
printf("%-10s%-5d 男 %4.1f\n",prep->name,prep->num,prep->score);
}else{
printf("%-10s%-5d 女 %4.1f\n",prep->name,prep->num,prep->score);
}
}
printf("show successful! anykey to return\n");
fflush(stdin);
getchar();
menu();
}

//添加数据---------------------------------------------------------------------------------
void Add(){
IfHeadEmpty();
char aname[10];
int anum=0;
int asex=0;
double ascore=0;
printf("enter data:");
fflush(stdin);
scanf("%s%d%d%lf",aname,&anum,&asex,&ascore);
// printf("%s%-5d %d %4.1f\n",aname,anum,asex,ascore);
ListInsert(aname,anum,asex,ascore);

printf("add successful! anykey to return\n");
fflush(stdin);
getchar();
menu();
}

//查询功能---------------------------------------------------------------------------------
void Search(){
IfHeadEmpty();
struct STUDENT *prep,*p;
prep = ListHead;
p=ListHead->next;

int i;
char sname[10];
int snumsex;
double sscore;
int isfind=0;
//printf("%-10s%-5d %d %4.1f\n",name,num,sex,score);
printf("which methed you choose:1.name 2.num 3.sex 4.score 0.exit\n");
scanf("%d",&i);
switch(i){
case 0:menu();
case 1:
printf("enter the name you are looking for:");
scanf("%s",sname);
while(p)
{
prep = p;
p = p->next;
if(strcmp(prep->name,sname)==0)
{
printf("%-10s%-5d %d %4.1f\n",prep->name,prep->num,prep->sex,prep->score);
isfind = 1;
}
}
break;
case 2:
printf("enter the num you are looking for:");
scanf("%d",&snumsex);
while(p)
{
prep = p;
p =p->next;
if(prep->num==snumsex)
{
printf("%-10s%-5d %d %4.1f\n",prep->name,prep->num,prep->sex,prep->score);
isfind = 2;
}
}
break;
case 3:
printf("enter the sex you are looking for:");
scanf("%d",&snumsex);
while(p)
{
prep = p;
p =p->next;
if(prep->sex==snumsex)
{
printf("%-10s%-5d %d %4.1f\n",prep->name,prep->num,prep->sex,prep->score);
isfind = 3;
}
}
break;
case 4:
printf("enter the score you are looking for:");
scanf("%lf",&sscore);
while(p)
{
prep = p;
p =p->next;
if(prep->score==sscore)
{
printf("%-10s%-5d %d %4.1f\n",prep->name,prep->num,prep->sex,prep->score);
isfind = 4;
}
}
break;
default:
printf("error number,re-enter:\n");
Search();
}

if(isfind!=0)
printf("Search successful! press any ket to return\n");
else
printf("Search failed! press any ket to return\n");
fflush(stdin);
getchar();
// setbuf(stdin,"4\r");
// ungetc('4',stdin);
// sscanf("4","%d",stdin);
// menu();
Search();

}

//排序功能---------------------------------------------------------------------------------
void Rank(){
IfHeadEmpty();
struct STUDENT *prep,*p,*key;
int i=0,j=1;
// double isequal;
// printf("%-10s%-5d %d %4.1f\n",name,num,sex,score);
printf("sort by: 1.name 2.num 3.sex 4.score 0.exit\n");
scanf("%d",&i);
if(i<1 || i>4)
{
printf("wrong choose,re-enter:\n");
Rank();
}
printf("order: 1.positive 0.reverse\n");
scanf("%d",&j);
if(j<0 || j>1)
{
printf("wrong choose,re-enter:\n");
Rank();
}
switch(i){
case 0:menu(); //选择排序法：将第一个数的备份与后排比较，小于它的就将他赋值给备份交换（指针代表原数），一行循环接收进行，再将第二个数进行如此循环
case 1:
prep = ListHead;
p=ListHead->next;
while(prep->next)
{
prep = prep->next;
p = prep->next;
key = prep;
while(p)
{
if(j)
{
if(strcmp(key->name,p->name) > 0)
key = p;
}else{
if(strcmp(key->name,p->name) < 0)
key = p;
}
p = p->next;
}
ExchangeNope(prep, key);
}
break;
case 2:
prep = ListHead;
p=ListHead->next;
while(prep->next)
{
prep = prep->next;
p = prep->next;
key = prep;
while(p)
{
if(j)
{
if((key->num-p->num) > 0)
key = p;
}else{
if((key->num-p->num) < 0)
key = p;
}
p = p->next;
}
ExchangeNope(prep, key);
}
break;
case 3:
prep = ListHead;
p=ListHead->next;
while(prep->next)
{
prep = prep->next;
p = prep->next;
key = prep;
while(p)
{
if(j)
{
if((key->sex-p->sex) > 0)
key = p;
}else{
if((key->sex-p->sex) < 0)
key = p;
}
p = p->next;
}
ExchangeNope(prep, key);
}
break;
case 4:
prep = ListHead;
p=ListHead->next;
while(prep->next)
{
prep = prep->next;
p = prep->next;
key = prep;
while(p)
{
if(j)
{
if((key->score-p->score) > 0)
key = p;
}else{
if((key->score-p->score) < 0)
key = p;
}
p = p->next;
}
ExchangeNope(prep, key);
}
break;
default:printf("wrong choose,re-enter:");
Rank();
}
Show();
printf("Rank successful!any key to return;\n");
fflush(stdin);
getchar();
menu();

}

//删除---------------------------------------------------------------------------------
void Delete(){
IfHeadEmpty();
struct STUDENT *prep,*p,*del;
prep = ListHead;
p=ListHead->next;

int i;
int isfind=0;
char *dname;
int dnumsex;
double dscore;

printf("select a method: 1.name 2.num 3.sex 4.score 0.exit\n");
scanf("%d",&i);
switch(i){
case 0:menu();
case 1:
printf("enter the name:\n");
scanf("%s",dname);
while(p)
{

if(!strcmp(p->name,dname))
{
prep->next = p->next;
del = p;
printf("%-10s%-5d %d %4.1f(已删除)\n",del->name,del->num,del->sex,del->score);
free(p);
p = prep->next;
isfind = 1;
}else{
prep = p;
p =p->next;
// isfind = 0;
}
}
break;
case 2:
printf("enter the num:\n");
scanf("%d",&dnumsex);
while(p)
{

if(!(p->num-dnumsex))
{
prep->next = p->next;
del = p;
printf("%-10s%-5d %d %4.1f(已删除)\n",del->name,del->num,del->sex,del->score);
free(p);
p = prep->next;
isfind = 1;
}else{
prep = p;
p =p->next;
// isfind = 0;
}
}
break;
case 3:
printf("enter the sex:\n");
scanf("%d",&dnumsex);
while(p)
{

if(!(p->sex-dnumsex))
{
prep->next = p->next;
del = p;
printf("%-10s%-5d %d %4.1f(已删除)\n",del->name,del->num,del->sex,del->score);
free(p);
p = prep->next;
isfind = 1;
}else{
prep = p;
p =p->next;
// isfind = 0;
}
}
break;
case 4:
printf("enter the score:\n");
scanf("%lf",&dscore);
while(p)
{

if(!(p->score-dscore))
{
prep->next = p->next;
del = p;
printf("%-10s%-5d %d %4.1f(已删除)\n",del->name,del->num,del->sex,del->score);
free(p);
p = prep->next;
isfind = 1;
}else{
prep = p;
p =p->next;
// isfind = 0;
}
}
break;
default:
printf("wrong choose,re-enter:");
Delete();
}
if(isfind)
printf("Delete successful!\n");
else
printf("Delete failed!\n");
printf("there is the current list:\n");
Show();
fflush(stdin);
printf("press any key to continue");
getchar();
menu();
}

//导出档案---------------------------------------------------------------------------------
void Export(){
IfHeadEmpty();
FILE *fp;
char save[15];
int i;
printf("enter the save name:\n");
fflush(stdin);
/// printf("if wrong????????????????????\n");
scanf("%s",save); //字符串键入只能用字符串数组接收不能用指针变量
// printf("if wrong????????????????????\n");
fp = fopen(save,"r");
// printf("if wrong????????????????????\n");
if(fp!=NULL)
{
printf("Whether covered: 1.Yse 0.No:\n");
fflush(stdin);
scanf("%d",&i);
if(i)
WriteList(save);
else
Export();
fclose(fp);
}else{
WriteList(save);

}

printf("Export successful! press any key to continue");
fflush(stdin);
getchar();
menu();

}

//退出-----------------------------------------------------------------------------------------
void Exit(){
exit(0);
}

//链表相关函数---------------------------------------------------------------------------------
struct STUDENT* CreatListHead(){
struct STUDENT* p;
p = (struct STUDENT*)malloc(sizeof(struct STUDENT));//结构体指针创建后一定要初始化！！！
p->next = NULL;
return p;
}

void ListInsert(char *name,int num,int sex,double score){
//printf("%-10s%-5d %d %4.1f\n",name,num,sex,score);
struct STUDENT *prep,*p;
prep = ListHead;
p=ListHead->next;
printf("%-10s%-5d %d %4.1f\n",name,num,sex,score);
while(p)
{
prep = p;
p =p->next;
}
p = (struct STUDENT*)malloc(sizeof(struct STUDENT));
strcpy(p->name,name);
p->num = num;
p->sex = sex;
p->score = score;
p->next = NULL;
prep->next = p;
}

void IfListBlank(){
struct STUDENT *prep,*p;
int i=0;
prep = ListHead;
p=ListHead->next;
while(p)
{
prep = p;
p =p->next;
i++;
}
printf("%d",i);
}

void ExchangeNope(struct STUDENT *p,struct STUDENT *q){
char exchar[10];
int exint;
double exdouble;

strcpy(exchar , p->name);
strcpy(p->name , q->name);
strcpy(q->name , exchar);
exint = p->num;
p->num = q->num;
q->num = exint;
exint = p->sex;
p->sex = q->sex;
q->sex = exint;
exdouble = p->score;
p->score = q->score;
q->score = exdouble;
}

void DeleteNode(struct STUDENT *d){
struct STUDENT *prep,*p,*del;
prep = ListHead;
p=ListHead->next;

while(p)
{
if(prep==d)
{
prep->next = p->next;
del = p;
printf("%-10s%-5d %d %4.1f(已删除)\n",del->name,del->num,del->sex,del->score);
prep = p->next;
p = prep->next;
free(del);
break;
}else{
prep = p;
p =p->next;
}
}
}

void WriteList(char *path){
struct STUDENT *p;
// prep = ListHead;
p = ListHead->next;

FILE *fpin;
fpin = fopen(path,"w");

while(p)
{
// fwrite(p,sizeof(p),1,fpin);
fprintf(fpin,"%-10s%-5d %d %4.1f\n",p->name,p->num,p->sex,p->score);
printf("%-10s%-5d %d %4.1f(已写入)\n",p->name,p->num,p->sex,p->score);
p = p->next;
}
fclose(fpin);
}

void IfHeadEmpty(){
if(ListHead==NULL){
printf("please import!\n");
getchar();
menu();
}
}