我想尽快知道这道C语言题的解法

Question

学生成绩管理。学生信息：姓名、性别、省份、电话号码。设计一个菜单程序，选择数字键1~3分别实现：输入学生信息、删除指定学生及信息和显示指定学生信息，选择数字4则回到操作系统状态。（用文件完成）

Answer 1

#include<stdio.h> /*引用库函数*/
#include<stdlib.h>
#include<ctype.h>
#include<string.h>
typedef struct /*定义结构体数组*/
{
char num[10]; /*学号*/
char name[20]; /*姓名*/
int score; /*成绩*/
}Student;
Student stu[80]; /*结构体数组变量*/
int menu_select() /*菜单函数*/
{
char c;
do{
system("cls"); /*运行前清屏*/
printf("\t\t****Students' Grade Management System****\n"); /*菜单选择*/
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(); /*读入选择*/
}while(c<'0'||c>'9');
return(c-'0'); /*返回选择*/
}
int Input(Student stud[],int n) /*输入若干条记录*/
{int i=0;
char sign,x[10]; /*x[10]为清除多余的数据所用*/
while(sign!='n'&&sign!='N') /*判断*/
{ printf("\t\t\tstudent's num:"); /*交互输入*/
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); /*清除多余的输入*/
printf("\t\t\tany more records?(Y/N)");
scanf("\t\t\t%c",&sign); /*输入判断*/
i++;
}
return(n+i);
}
void Display(Student stud[],int n) /*显示所有记录*/
{
int i;
printf("\t\t\t-----------------------------------\n"); /*格式头*/
printf("\t\t\tnumber name score\n");
printf("\t\t\t-----------------------------------\n");
for(i=1;i<n+1;i++) /*循环输入*/
{
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) /*每十个暂停*/
{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) /*按学号排序*/
{ 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) /*插入一条记录*/
{char x[10]; /*清除多余输入所用*/
printf("\t\t\tstudent's num:"); /*交互式输入*/
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); /*调用排序函数*/
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，删除一条记录*/
{ char s[20];
int i=0,j;
printf("\t\t\ttell me his(her) name:"); /*交互式问寻*/
scanf("%s",s);
while(strcmp(stud[i].name,s)!=0&&i<n) i++; /*查找判断*/
if(i==n)
{ printf("\t\t\tnot find!\n"); /*返回失败信息*/
return(n);
}
for(j=i;j<n-1;j++) /*删除操作*/
{
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) /*查找并显示一个记录*/
{ char s[20];
int i=0;
printf("\t\t\tinput his(her) name:"); /*交互式输入*/
scanf("\t\t\t%s",s);
while(strcmp(stud[i].name,s)!=0&&i<n) i++; /*查找判断*/
if(i==n)
{ printf("\t\t\tnot find!\n"); /*输入失败信息*/
return;

}
printf("\t\t\this(her) number:%s\n",stud[i].num); /*输出该学生信息*/
printf("\t\t\this(her) score:%d\n",stud[i].score);
}
void Statistic(Student stud[],int n) /*新增功能，输出统计信息*/
{ int i,j=0,k=0,sum=0;
float aver; /*成绩平均值*/
for(i=0;i<n;i++) /*循环输入判断*/
{
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); /*总共记录数*/
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) /*从文件中读入数据*/
{ int i=0,num;
FILE *fp; /*定义文件指针*/
char filename[20]; /*定义文件名*/
printf("\t\t\tInput the filename:");
scanf("\t\t\t%s",filename); /*输入文件名*/
if((fp=fopen(filename,"rb"))==NULL) /*打开文件*/
{ printf("\t\t\tcann't open the file\n"); /*打开失败信息*/
printf("\t\t\t");
system("pause");
return(n);
}
fscanf(fp,"%d",&num); /*读入总记录量*/
while(i<num) /*循环读入数据*/
{
fscanf(fp,"%s%s%d",stud[n+i].num,stud[n+i].name,&stud[n+i].score);
i++;
}
n+=num;
fclose(fp); /*关闭文件*/
printf("\t\t\tSuccessed!\n");
printf("\t\t\t");
system("pause");
return(n);
}
void WritetoText(Student stud[],int n) /*将所有记录写入文件*/
{
int i=0;
FILE *fp; /*定义文件指针*/
char filename[20]; /*定义文件名*/
printf("\t\t\tWrite Records to a Text File\n"); /*输入文件名*/
printf("\t\t\tInput the filename:");
scanf("\t\t\t%s",filename);
if((fp=fopen(filename,"w"))==NULL) /*打开文件*/
{
printf("\t\t\tcann't open the file\n");
system("pause");
return;
}
fprintf(fp,"%d\n",n); /*循环写入数据*/
while(i<n)
{
fprintf(fp,"%-16s%-15s%d\n",stud[i].num,stud[i].name,stud[i].score);
i++;
}
fclose(fp); /*关闭文件*/
printf("Successed!\n"); /*返回成功信息*/
}
void main() /*主函数*/
{
int n=0;
for(;;)
{
switch(menu_select()) /*选择判断*/
{
case 1:
printf("\t\t\tInput Records\n"); /*输入若干条记录*/
n=Input(stu,n);
break;
case 2:
printf("\t\t\tDisplay All Records\n"); /*显示所有记录*/
Display(stu,n);
break;
case 3:
printf("\t\t\tSort\n");
Sort_by_num(stu,n); /*按学号排序*/
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); /*插入一条记录*/
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，删除一条记录*/
printf("\t\t\t");
system("pause");
break;
case 6:
printf("\t\t\tQuery\n");
Query_a_record(stu,n); /*查找并显示一个记录*/
printf("\t\t\t");
system("pause");
break;
case 7:
printf("\t\t\tStatistic\n");
Statistic(stu,n); /*新增功能，输出统计信息*/
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，输出统计信息*/
break;
case 9:
printf("\t\t\tWrite to a Text file\n");
WritetoText(stu,n); /*循环写入数据*/
printf("\t\t\t");
system("pause");
break;
case 0:
printf("\t\t\tHave a Good Luck,Bye-bye!\n"); /*结束程序*/
printf("\t\t\t");
system("pause");
exit(0);
}
}
}

Answer 2

看看这个，看看是否对你有所启发
/* Note:Your choice is C IDE */
#include "stdio.h"
#include "string.h"
#include "stdlib.h"
#include "ctype.h"
#include "math.h"

#define N 3 /*这是总的学生数,你可以想多少就多少*/

char name[N][20];
int i,num[N];
float yuwen[N],shuxue[N],yingyu[N];

int input()
{
for(i=0;i<N;i++)
{
printf("请输入第[%d]学生的姓名\n",i+1);
scanf("%s",name[i]);
printf("请输入第[%d]学生的学号\n",i+1);
scanf("%d",&num[i]);
printf("请输入第[%d]学生的语文成绩\n",i+1);
scanf("%f",&yuwen[i]);
printf("请输入第[%d]学生的数学成绩\n",i+1);
scanf("%f",&shuxue[i]);
printf("请输入第[%d]学生的英语成绩\n",i+1);
scanf("%f",&yingyu[i]);
}
return(i);
}

void sort1()
{
int n;
float t;
int i,j;
char a[10];
for(i=0;i<N-1;i++)
for(j=i+1;j<N;j++)
{
if(num[i]>num[j]) /*条件成立，交换前后学号*/
{ n=num[j];
num[j]=num[i];
num[i]=n;

strcpy(a,name[j]); /*交换前后姓名，使与学号相对应*/
strcpy(name[j],name[i]);
strcpy(name[i],a);

t=yuwen[j]; /*交换前后语文成绩，使与学号想对应*/
yuwen[j]=yuwen[i];
yuwen[i]=t;

t=shuxue[j]; /*交换前后数学成绩，使与学号想对应*/
shuxue[j]=shuxue[i];
shuxue[i]=t;

t=yingyu[j]; /*交换前后英语成绩，使与学号想对应*/
yingyu[j]=yingyu[i];
yingyu[i]=t;
}
}
printf("学生成绩按学号排序:\n");
printf("姓名\t学号\t语文成绩\t数学成绩\t英语成绩\n");
for(i=0;i<N;i++)
printf("%s\t%d\t%.2f\t\t%.2f\t\t%.2f\n",name[i],num[i],yuwen[i],shuxue[i],yingyu[i]);

}
void sort2()
{
int i,j;
float t;
char a[10];
int b;
for(i=0;i<N-1;i++)
for(j=i+1;j<N;j++)
{
if(yuwen[j]+shuxue[j]+yingyu[j]>yuwen[i]+shuxue[i]+yingyu[i])
{b=num[i];
num[i]=num[j];
num[j]=b;

strcpy(a,name[j]);/*交换前后姓名，使与学号相对应*/
strcpy(name[j],name[i]);
strcpy(name[i],a);

t=yuwen[i]; /*交换前后语文成绩，使与学号想对应*/
yuwen[i]=yuwen[j];
yuwen[j]=t;

t=shuxue[i]; /*交换前后数学成绩，使与学号想对应*/
shuxue[i]=shuxue[j];
shuxue[j]=t;

t=yingyu[i]; /*交换前后英语成绩，使与学号想对应*/
yingyu[i]=yingyu[j];
yingyu[j]=t;
}
}
printf("学生成绩按总分排序:\n");
printf("姓名\t学号\t总分\n");
for(i=0;i<N;i++)
{
printf("%s\t%d\t%.2f",name[i],num[i],yuwen[i]+shuxue[i]+yingyu[i]);
printf("\n");
}

}

void stat()
{
int i,j;
float max1,max2,max3,min1,min2,min3;
float sum1=0,sum2=0,sum3=0;
float aver1,aver2,aver3;
printf("姓名\t学号\t语文\t数学\t英语\t总分\t平均分\n");
for(i=0;i<N;i++)
{
printf("%s\t%d\t%.2f\t%.2f\t%.2f\t%.2f\t%.2f",name[i],num[i],yuwen[i],shuxue[i],yingyu[i],
yuwen[i]+shuxue[i]+yingyu[i],(yuwen[i]+shuxue[i]+yingyu[i])/3);
printf("\n");
}

for(i=0;i<N;i++) /*求总分*/
{

sum1=sum1+yuwen[i];
sum2=sum2+shuxue[i];
sum3=sum3+yingyu[i];
}
aver1=sum1/N;/*求平均分*/
aver2=sum2/N;
aver3=sum3/N;

max1=yuwen[N-1];min1=yuwen[0];/*求语文成绩的最高分和最低分*/
for(j=0;j<N;j++)
{
if(max1<yuwen[j])
max1=yuwen[j];
if(min1>yuwen[j])
min1=yuwen[j];
}

max2=shuxue[N-1];min2=shuxue[0]; /*求数学成绩的最高分和最低分*/
for(j=0;j<N;j++)
{
if(max2<shuxue[j])
max2=shuxue[j];
if(min2>shuxue[j])
min2=shuxue[j];
}

max3=yingyu[N-1];min3=yingyu[0];/*求英语成绩的最高分和最低分*/
for(j=0;j<N;j++)
{
if(max3<yingyu[j])
max3=yingyu[j];
if(min3>yingyu[j])
min3=yingyu[j];
}

printf("语文成绩统计:\n");
printf("平均分:%.2f\t""最高分:%.2f\t""最低分:%.2f\n",aver1,max1,min1);

printf("数学成绩统计:\n");
printf("平均分:%.2f\t""最高分:%.2f\t""最低分:%.2f\n",aver2,max2,min2);

printf("英语成绩统计:\n");
printf("平均分:%.2f\t""最高分:%.2f\t""最低分:%.2f\n",aver3,max3,min3);
}

void main()
{ int k;
while(1)
{
printf("*******************学生成绩管理系统*********************\n");
printf("\t\t | 1. 输入学生资料 |\n");
printf("\t\t | 2. 学生成绩排序 |\n");
printf("\t\t | 3. 学生成绩统计 |\n");
printf("\t\t | 0. 退出 |\n");
printf("********************************************************\n");
printf("请输入(0~3)选择：");
scanf("%d",&k);
switch(k) /*用switch语句实现功能选择*/
{
case 1: input();break;/*输入学生资料函数*/
case 2: sort1();sort2();break;/*成绩排序函数*/
case 3: stat();break;/*成绩统计函数*/
case 0: exit(0);break;/*退出*/
}
}
}

Answer 3

先设计一个类：学生类。把学生信息声明成私有数据成员。用switch语句实现菜单命令的跳转。最要用动态链表的知识将输入、删除、显示、遍历等成员函数。4是用return语句实现的。在每个数据操作中声明一个流对象，文件来实现。