数据结构课程设计——学生成绩管理

#include<stdio.h>
#include<string.h>
#include <malloc.h>
#include <stdlib.h>
#include<conio.h>
#define LEN sizeof(struct student)
typedef struct student
{
long numb;
int chinese;
int math;
int english;
int totalscore;
char name[12];
struct student *next;
} STU;
//声明部
STU* creat();
void output(STU *head);
STU* creatByN(int num);
STU* findByNumb(STU *head, long num);
STU* findByNumbEx(STU *head, long num, STU **ppBefore);
STU* findByName(STU *head, char *name);
void find(STU *head);
STU* del(STU *head);
STU* insert(STU *head);
void update(STU *head);
STU* sort(STU *head);
void save_info(STU *head);
STU *load_info();
void Backup_info(STU *head);
int n;//全局变量
void main()
{
STU *head;
int choice;

for(;;)
{
system("cls");/*清屏*/
printf("\t************************\t\n");
printf("\t*欢迎使用成绩管理系统\t\n");
printf("\t* 1:输入信息\t\n");
printf("\t* 2:显示全部信息\t\n");
printf("\t* 3:删除\t\n");
printf("\t* 4:查找\t\n");
printf("\t* 5:插入\t\n");
printf("\t* 6:修改\t\n");
printf("\t* 7:排序\t\n");
printf("\t* 8:保存文件\t\n");
printf("\t* 9:文件加载\t\n");
printf("\t* 10:备份\t\n");
printf("\t* 0:退\t\n");
printf("\t************************\t\n");
printf("*请输入数字(0-9)进行功能选择 :");
scanf("%d",&choice);
if(choice==0) break;
switch(choice)
{
case 1:
head=creat();
break;
case 2:
output(head);
break;
case 3:
head=del(head);
break;
case 4:
find(head);
break;
case 5:
head=insert(head);
break;
case 6:
update(head);
break;
case 7:
head=sort(head);
break;
case 8:
save_info(head);
break;
case 9:
head=load_info();
break;
case 10:
Backup_info(head);
break;
}
printf("按任意键继续....\n");
getch();/*暂停*/
}
printf("欢迎使用再见\n");
}
STU *creat()/*创建链表*/
{
STU *head,*pnew,*ptail;
head=NULL;
n=0;//初始化
printf("现进行信息输入号输入0结束\n");
while(1)
{
//断申请新节点
pnew=(STU *)malloc(LEN);
printf("号\t姓名\t语文\t数\t英语\t总\n");
scanf("%ld",&pnew->numb);
if(pnew->numb==0)
break;
scanf("%s",pnew->name);
scanf("%d%d%d",&pnew->chinese,&pnew->math,&pnew->english);
pnew->totalscore=0;
pnew->totalscore=pnew->chinese+pnew->math+pnew->english;
pnew->next=NULL;//节点连接链表尾部
n++;
if(n==1)
{
head=pnew;
ptail=pnew;
}
else
{
ptail->next=pnew;
ptail=pnew;
}//算思路让pnew指向新辟结点,ptail指向链表结点,pnew所指结点连接ptail所指结点面,用"ptail->next=pnew"实现.
}
return head;//能head进行赋值,所返值
}

void output(STU *head)
{
STU *p;//定义指针,使其断移完输
printf("前共%d节点：\n",n);
printf("号\t姓名\t语文\t数\t英语\t总\n");
for(p=head; p!=NULL; p=p->next)
printf("%ld\t%s\t%d\t%d\t%d\t%d\n",p->numb,p->name,p->chinese,p->math,p->english,p->totalscore);
}//变返
struct student *creatByN(int num)
{
STU *head,*pnew,*ptail;
int i;
//链表初始化
head=NULL;
n=0;
//链表创建循环
for(i=0; i<num; i++)
{
//获节点并赋值节点由pnew指向
pnew=(STU *)malloc(LEN);
printf("号\t姓名\t语文\t数\t英语\t总\n");
scanf("%ld",&pnew->numb);
scanf("%s",pnew->name);
scanf("%d%d%d",&pnew->chinese,&pnew->math,&pnew->english);
pnew->next=NULL;//pnew所指向节点插入链表尾部
n++;
if(n==1)
{
head=pnew;
ptail=pnew;
}
else
{
ptail->next=pnew;
ptail=pnew;
}
}
return head;
}
STU* findByNumb(STU *head, long num)
{
STU *p,*presult;
presult=NULL;
for(p=head; p!=NULL; p=p->next)
if(p->numb==num)
{
presult=p;//记录指针位置
break;
}
return presult;
}
STU* findByName(STU *head, char *name)
{
STU *p,*presult;
presult=NULL;
for(p=head; p!=NULL; p=p->next)
if(strcmp(p->name,name)==0)
{
presult=p;
break;
}
return presult;//位置变更返值
}
STU* findByNumbEx(STU *head, long num, STU **ppBefore)
{
STU *p,*presult,*pBefore;
presult=pBefore=NULL;
for(p=head; p!=NULL; pBefore=p,p=p->next) //记录指针前位置
if(p->numb==num)
{
presult=p;
break;
}
*ppBefore=pBefore;
return presult;
}
void find(STU *head)
{
int num,choice;
STU *pr;
char name[12];
printf("输入要查找式（1:按号2:按姓名）：");
scanf("%d",&choice);
if(choice==1)
{
printf("输入要查找号：");
scanf("%ld",&num);
pr=findByNumb(head,num);
}
else if(choice==2)
{
printf("输入要查找姓名：");
scanf("%s",name);
pr=findByName(head,name);
}
if(pr==NULL)
printf("起,查\n");
else
{
printf("找该信息：\n");
printf("号\t姓名\t语文\t数\t英语\t总\n");
printf("%ld\t%s\t%d\t%d\t%d\n",pr->numb,pr->name,pr->chinese,pr->math,pr->english,pr->totalscore);
}
}
void update(STU *head)
{
int num;
STU *pr;
printf("输入要查找号：");
scanf("%ld",&num);
pr=findByNumb(head,num);
if(pr==NULL)
printf("起,查\n");
else
{
printf("找该信息：\n");
printf("号\t姓名\t语文\t数\t英语\t总\n");
printf("%ld\t%s\t%d\t%d\t%d\n",pr->numb,pr->name,pr->chinese,pr->math,pr->english);
printf("请输入修改信息\n");
printf("号\t姓名\t语文\t数\t英语\t总\n");
scanf("%ld%s%d%d%d%d",&pr->numb,&pr->name,&pr->chinese,&pr->math,&pr->english);
pr->totalscore=0;
pr->totalscore=pr->chinese+pr->math+pr->english;
}
}
STU* del(STU *head)
{
long num;
STU *pCur,*pBefore;
//查找要删除节点用pCur记录该节点
printf("输入要删除号：");
scanf("%ld",&num);
pCur=findByNumbEx(head,num,&pBefore);
//该节点存进行删除
if(pCur!=NULL)
{
n--;//记录删除节点数
//根据pCur所指节点位置进行判断：节点或续节点
//删除节点
if(pCur==head)
{
head=pCur->next;
}
//删除续节点
else
{
//获取前向节点指针pBefore

//利用pBeforepCur完删除
pBefore->next=pCur->next;
}
}
return head;
}
STU* insert(STU *head)
{
STU *pCur,*pnew,*pBefore,*p;
//申请新节点并赋值
pnew=(STU *)malloc(LEN);
printf("号\t姓名\t语文\t数\t英语\t总\n");
scanf("%d",&pnew->numb);
scanf("%s",&pnew->name);
scanf("%d%d%d",&pnew->chinese,&pnew->math,&pnew->english);
pnew->totalscore=0;
pnew->totalscore=pnew->chinese+pnew->math+pnew->english;
pnew->next=NULL;
if(head==NULL)//链表空
head=pnew;
else //链表空
{
//找位置即获取pCur
for(p=head; p!=NULL; pBefore=p,p=p->next)
if(p->numb > pnew->numb)
{
pCur=p;
break;
}
//没找pCur则应pnew插入尾节点
if(p==NULL)
{
pBefore->next=pnew;
}
//找pCur则应pnew插入pCur前根据pCur位置：结点前间节点前两种情况
else
{
//pCur结点
if(pCur==head)
{
pnew->next=pCur;
head=pnew;
}
//pCur间结点
else
{
pnew->next=pCur;
pBefore->next=pnew;
}
}
}
n++;
return head;
}
STU* sort(STU *head)
{
STU *first; /*排列序链表指针*/
STU *tail; /*排列序链表尾指针*/
STU *p_min; /*保留键值更节点前驱节点指针*/
STU *min; /*存储节点*/
STU *p; /*前比较节点*/
(STU *)malloc(LEN);
first = NULL;
while (head != NULL) /*链表找键值节点*/
{
/*注意：for语句体现选择排序思想*/
for (p=head,min=head; p->next!=NULL; p=p->next) /*循环遍历链表节点找节点*/
{
if (p->next->totalscore < min->totalscore) /*找比前min节点*/
{
p_min = p; /*保存找节点前驱节点：显p->next前驱节点p*/
min = p->next; /*保存键值更节点*/
}
}
/*面for语句结束要做两件事；放入序链表；二根据相应条件判断安排离原链表*/
/*第件事*/
if (first == NULL) /*序链表目前空链表*/
{
first = min; /*第找键值节点*/
tail = min; /*注意：尾指针让指向节点*/
}
else /*序链表已经节点*/
{
tail->next = min; /*刚找节点放即让尾指针next指向*/
tail = min; /*尾指针要指向*/
}
/*第二件事*/
if (min == head) /*找节点第节点*/
{
head = head->next; /*显让head指向原head->next,即第二节点OK*/
}
else /*第节点*/
{
p_min->next = min->next; /*前节点next指向前minnext,让min离原链表*/
}
}
if (first != NULL) /*循环结束序链表first*/
{
tail->next = NULL; /*单向链表节点next应该指向NULL*/
}
head = first;
return head;
}
//保存
void save_info(STU *head)
{
STU *p;
FILE *fp;
char filename[20];
printf("输入保存文件文件名：");
scanf("%s",filename);
if((fp=fopen(filename,"w"))==NULL)
{
printf("can not open the file");
exit(0);
}
fprintf(fp,"前共%d节点：\n",n);
fprintf(fp,"号\t姓名\t语文\t数\t英语\t总\n");
for(p=head; p!=NULL; p=p->next)
fprintf(fp,"%ld\t%s\t%d\t%d\t%d%\t%d\n",p->numb,p->name,p->chinese,p->math,p->english,p->totalscore);
fclose(fp);
printf("保存功\n");
}
//加载
STU *load_info()
{
STU *head,*pnew,*ptail;
FILE *fp;
char filename[20],secondLine[20];
int num,i;
printf("输入读取文件文件名：");
scanf("%s",filename);
if((fp=fopen(filename,"r"))==NULL)
{
printf("can not open the file");
exit(0);
}
fscanf(fp,"前共%d节点：",&num);

//滤第二行
for(i=0; i<6; i++)
fscanf(fp,"%s",secondLine);
//链表初始化
head=NULL;
n=0;
//链表创建循环
for(i=0; i<num; i++)
{
//获节点并赋值节点由pnew指向
pnew=(STU *)malloc(LEN);
fscanf(fp,"%ld%s%d%d%d%d",&pnew->numb,&pnew->name,&pnew->chinese,&pnew->math,&pnew->english,&pnew->totalscore);
pnew->next=NULL;
//pnew所指向节点插入链表尾部
n++;//记录加载节点数
if(n==1)
{
head=pnew;
ptail=pnew;
}
else
{
ptail->next=pnew;
ptail=pnew;
}
}
fclose(fp);
printf("读取功\n");
return head;
}
void Backup_info(STU *head)//备份
{
FILE *in,*out;
char infile[10],outfile[10];
printf("Enter the inflie name:\n");
scanf("%s",infile);
printf("Enter the outflie name:\n");
scanf("%s",outfile);
if((in=fopen(infile,"r"))==NULL)
{
printf("cannot open infile\n");
exit(0);
}
if((out=fopen(outfile,"w"))==NULL)
{
printf("cannot open outfile\n");
exit(0);
}
while(! feof(in)) fputc(fgetc(in),out);
fclose(in);
fclose(out);
printf("备份成功\n");
}