#include<stdio.h> /*引用庫函數*/ 
#include<stdlib.h> 
#include<ctype.h> 
#include<string.h> 
typedef struct /*定義結構體數組*/ 
{ 
char num[10]; /*學號*/ 
char name[20]; /*姓名*/ 
int score; /*成績*/ 
}Student; 
Student stu[80]; /*結構體數組變量*/ 
int menu_select() /*菜單函數*/ 
{ 
char c; 
do{ 
system("cls"); /*運行前清屏*/ 
printf("\t\t****Students' Grade Management System****\n"); /*菜單選擇*/ 
printf("\t\t | 1. Input Records |\n"); 
printf("\t\t | 2. Display All Records |\n"); 
printf("\t\t | 3. Sort |\n"); 
printf("\t\t | 4. Insert a Record |\n"); 
printf("\t\t | 5. Delete a Record |\n"); 
printf("\t\t | 6. Query |\n"); 
printf("\t\t | 7. Statistic |\n"); 
printf("\t\t | 8. Add Records from a Text File|\n"); 
printf("\t\t | 9. Write to a Text file |\n"); 
printf("\t\t | 0. Quit |\n"); 
printf("\t\t*****************************************\n"); 
printf("\t\t\tGive your Choice(0-9):"); 
c=getchar(); /*讀入選擇*/ 
}while(c<'0'||c>'9'); 
return(c-'0'); /*返回選擇*/ 
} 
int Input(Student stud[],int n) /*輸入若干條記錄*/ 
{int i=0; 
char sign,x[10]; /*x[10]為清除多余的數據所用*/ 
while(sign!='n'&&sign!='N') /*判斷*/ 
{ printf("\t\t\tstudent's num:"); /*交互輸入*/ 
scanf("\t\t\t%s",stud[n+i].num); 
printf("\t\t\tstudent's name:"); 
scanf("\t\t\t%s",stud[n+i].name); 
printf("\t\t\tstudent's score:"); 
scanf("\t\t\t%d",&stud[n+i].score); 
gets(x); /*清除多余的輸入*/ 
printf("\t\t\tany more records?(Y/N)"); 
scanf("\t\t\t%c",&sign); /*輸入判斷*/ 
i++; 
} 
return(n+i); 
} 
void Display(Student stud[],int n) /*顯示所有記錄*/ 
{ 
int i; 
printf("\t\t\t-----------------------------------\n"); /*格式頭*/ 
printf("\t\t\tnumber name score\n"); 
printf("\t\t\t-----------------------------------\n"); 
for(i=1;i<n+1;i++) /*循環輸入*/ 
{ 
printf("\t\t\t%-16s%-15s%d\n",stud[i-1].num,stud[i-1].name,stud[i-1].score); 
if(i>1&&i%10==0) /*每十個暫停*/ 
{printf("\t\t\t-----------------------------------\n"); /*格式*/ 
printf("\t\t\t"); 
system("pause"); 
printf("\t\t\t-----------------------------------\n"); 
} 
} 
printf("\t\t\t"); 
system("pause"); 
} 
void Sort_by_num(Student stud[],int n) /*按學號排序*/ 
{ int i,j,*p,*q,s; 
char t[10]; 
for(i=0;i<n-1;i++) /*冒泡法排序*/ 
for(j=0;j<n-1-i;j++) 
if(strcmp(stud[j].num,stud[j+1].num)>0) 
{strcpy(t,stud[j+1].num); 
strcpy(stud[j+1].num,stud[j].num); 
strcpy(stud[j].num,t); 
strcpy(t,stud[j+1].name); 
strcpy(stud[j+1].name,stud[j].name); 
strcpy(stud[j].name,t); 
p=&stud[j+1].score; 
q=&stud[j].score; 
s=*p; 
*p=*q; 
*q=s; 
} 
} 
int Insert_a_record(Student stud[],int n) /*插入一條記錄*/ 
{char x[10]; /*清除多余輸入所用*/ 
printf("\t\t\tstudent's num:"); /*交互式輸入*/ 
scanf("\t\t\t%s",stud[n].num); 
printf("\t\t\tstudent's name:"); 
scanf("\t\t\t%s",stud[n].name); 
printf("\t\t\tstudent's score:"); 
scanf("\t\t\t%d",&stud[n].score); 
gets(x); 
n++; 
Sort_by_num(stud,n); /*調用排序函數*/ 
printf("\t\t\tInsert Successed!\n"); /*返回成功信息*/ 
return(n); 
} 
int Delete_a_record(Student stud[],int n) /*按姓名查找，刪除一條記錄*/ 
{ char s[20]; 
int i=0,j; 
printf("\t\t\ttell me his(her) name:"); /*交互式問尋*/ 
scanf("%s",s); 
while(strcmp(stud[i].name,s)!=0&&i<n) i++; /*查找判斷*/ 
if(i==n) 
{ printf("\t\t\tnot find!\n"); /*返回失敗信息*/ 
return(n); 
} 
for(j=i;j<n-1;j++) /*刪除操作*/ 
{ 
strcpy(stud[j].num,stud[j+1].num); 
strcpy(stud[j].name,stud[j+1].name); 
stud[j].score=stud[j+1].score; 
} 
printf("\t\t\tDelete Successed!\n"); /*返回成功信息*/ 
return(n-1); 
} 
void Query_a_record(Student stud[],int n) /*查找并顯示一個記錄*/ 
{ char s[20]; 
int i=0; 
printf("\t\t\tinput his(her) name:"); /*交互式輸入*/ 
scanf("\t\t\t%s",s); 
while(strcmp(stud[i].name,s)!=0&&i<n) i++; /*查找判斷*/ 
if(i==n) 
{ printf("\t\t\tnot find!\n"); /*輸入失敗信息*/ 
return; 

} 
printf("\t\t\this(her) number:%s\n",stud[i].num); /*輸出該學生信息*/ 
printf("\t\t\this(her) score:%d\n",stud[i].score); 
} 
void Statistic(Student stud[],int n) /*新增功能，輸出統計信息*/ 
{ int i,j=0,k=0,sum=0; 
float aver; /*成績平均值*/ 
for(i=0;i<n;i++) /*循環輸入判斷*/ 
{ 
sum+=stud[i].score; 
if(stud[j].score>stud[i].score) j=i; 
if(stud[k].score<stud[i].score) k=i; 
} 
aver=1.0*sum/n; 
printf("\t\t\tthere are %d records.\n",n); /*總共記錄數*/ 
printf("\t\t\tthe hignest score:\n"); /*最高分*/ 
printf("\t\t\tnumber:%s name:%s score:%d\n",stud[j].num,stud[j].name,stud[j].score); 
printf("\t\t\tthe lowest score:\n"); /*最低分*/ 
printf("\t\t\tnumber:%s name:%s score:%d\n",stud[k].num,stud[k].name,stud[k].score); 
printf("\t\t\tthe average score is %5.2f\n",aver); /*平均分*/ 
} 
int AddfromText(Student stud[],int n) /*從文件中讀入數據*/ 
{ int i=0,num; 
FILE *fp; /*定義文件指針*/ 
char filename[20]; /*定義文件名*/ 
printf("\t\t\tInput the filename:"); 
scanf("\t\t\t%s",filename); /*輸入文件名*/ 
if((fp=fopen(filename,"rb"))==NULL) /*打開文件*/ 
{ printf("\t\t\tcann't open the file\n"); /*打開失敗信息*/ 
printf("\t\t\t"); 
system("pause"); 
return(n); 
} 
fscanf(fp,"%d",&num); /*讀入總記錄量*/ 
while(i<num) /*循環讀入數據*/ 
{ 
fscanf(fp,"%s%s%d",stud[n+i].num,stud[n+i].name,&stud[n+i].score); 
i++; 
} 
n+=num; 
fclose(fp); /*關閉文件*/ 
printf("\t\t\tSuccessed!\n"); 
printf("\t\t\t"); 
system("pause"); 
return(n); 
} 
void WritetoText(Student stud[],int n) /*將所有記錄寫入文件*/ 
{ 
int i=0; 
FILE *fp; /*定義文件指針*/ 
char filename[20]; /*定義文件名*/ 
printf("\t\t\tWrite Records to a Text File\n"); /*輸入文件名*/ 
printf("\t\t\tInput the filename:"); 
scanf("\t\t\t%s",filename); 
if((fp=fopen(filename,"w"))==NULL) /*打開文件*/ 
{ 
printf("\t\t\tcann't open the file\n"); 
system("pause"); 
return; 
} 
fprintf(fp,"%d\n",n); /*循環寫入數據*/ 
while(i<n) 
{ 
fprintf(fp,"%-16s%-15s%d\n",stud[i].num,stud[i].name,stud[i].score); 
i++; 
} 
fclose(fp); /*關閉文件*/ 
printf("Successed!\n"); /*返回成功信息*/ 
} 
void main() /*主函數*/ 
{ 
int n=0; 
for(;;) 
{ 
switch(menu_select()) /*選擇判斷*/ 
{ 
case 1: 
printf("\t\t\tInput Records\n"); /*輸入若干條記錄*/ 
n=Input(stu,n); 
break; 
case 2: 
printf("\t\t\tDisplay All Records\n"); /*顯示所有記錄*/ 
Display(stu,n); 
break; 
case 3: 
printf("\t\t\tSort\n"); 
Sort_by_num(stu,n); /*按學號排序*/ 
printf("\t\t\tSort Suceessed!\n"); 
printf("\t\t\t"); 
system("pause"); 
break; 
case 4: 
printf("\t\t\tInsert a Record\n"); 
n=Insert_a_record(stu,n); /*插入一條記錄*/ 
printf("\t\t\t"); 
system("pause"); 
break; 
case 5: 
printf("\t\t\tDelete a Record\n"); 
n=Delete_a_record(stu,n); /*按姓名查找，刪除一條記錄*/ 
printf("\t\t\t"); 
system("pause"); 
break; 
case 6: 
printf("\t\t\tQuery\n"); 
Query_a_record(stu,n); /*查找并顯示一個記錄*/ 
printf("\t\t\t"); 
system("pause"); 
break; 
case 7: 
printf("\t\t\tStatistic\n"); 
Statistic(stu,n); /*新增功能，輸出統計信息*/ 
printf("\t\t\t"); 
system("pause"); 
break; 
case 8: 
printf("\t\t\tAdd Records from a Text File\n"); 
n=AddfromText(stu,n); /*新增功能，輸出統計信息*/ 
break; 
case 9: 
printf("\t\t\tWrite to a Text file\n"); 
WritetoText(stu,n); /*循環寫入數據*/ 
printf("\t\t\t"); 
system("pause"); 
break; 
case 0: 
printf("\t\t\tHave a Good Luck,Bye-bye!\n"); /*結束程序*/ 
printf("\t\t\t"); 
system("pause"); 
exit(0); 
} 
} 
}