版权声明：本文为博主原创文章。 https://blog.csdn.net/qq_41061352/article/details/79048656
问题描述：
现提供数据文件students.txt(本题目数据由程序随机生成，非真实数据),里面存放的是学生的信息，数据样例如下：
姓名,学号,性别,年龄,班级
张三,2017002871,男,17,大数据1702
李四,2017001765,女,18,软件工程1712
小路,2016009876,男,20,大数据1701
大张伟,2014002715,男,19,计算机1402
王璐丹,2017009479,女,22,大数据1702
张三,2015009321,男,22,信计1502
要求：
a) 读入students.txt里的数据存到内存,要求学生信息以结构体数组的方式存储。
b) 根据用户的输入在内存里查询学生信息，需要支持以下三种查询模式，需要提供给用户选择查询模式的菜单：
i. 查询模式1：根据姓名或学号查询学生信息
ii. 查询模式2：根据年龄范围查询学生信息
iii. 查询模式3：根据班级查询学生信息
3.输入输出样例：
a) 查询模式1
样例1：
输入：张三
输出：
张三,2017002871,男,17,大数据1702
张三,2015009321,男,22,信计1502
样例2：
输入： 2017009876
输出：
小路,2016009876,男,20,大数据1701
b) 查询模式2
样例1：
输入： 18 20
输出：
李四,2017001765,女,18,软件工程1712
小路,2016009876,男,20,大数据1701
大张伟,2014002715,男,19,计算机1402
c) 查询模式3
样例1：
输入：大数据1702
输出：
张三,2017002871,男,17,大数据1702
王璐丹,2017009479,女,22,大数据1702
这道题是简单的c语言练习，主要是练习结构体的使用以及文件的读取，以及读取时%[^]的使用
程序代码如下：
#include <stdio.h>
#include <string.h>
struct student
{
char name[30];
char number[30];
char sex[10];
int age;
char classes[30];
};
int main()
{
int num,num2,num3,num4;
long int num1;
FILE *fp;
char temp[30],mode[30];
struct student students[1000];
if((fp=fopen("./students.txt","r"))==NULL)//open the file
{
printf("can not open file students.txt,please check if the file is in the same path.\n");
system("pause");
exit(1);
}
for(num=0;!feof(fp);num++)//read the file
{
fscanf(fp,"%[^,],%[^,],%[^,],%d,%s\n",&students[num].number,students[num].name,students[num].sex,&students[num].age,students[num].classes);
}
while(1)
{
system("cls");
printf(" __________________________________________\n");
printf(" ----------|Welcome to the student information system|-----------\n");
printf(" ------------------------------------------\n");
printf(" |mode1:Query student information by name or student number. |\n");
printf(" |mode2:Inquire about student information according to age range.|\n");
printf(" |mode3:Check the student information according to the class. |\n");
printf(" |mode4:List all student information. |\n");
printf(" |There are %d student's information in the system |\n",num);
printf(" ---------------------------------------------------------------\n");
printf(" Please enter the query mode,enter is the return key.Enter 'q' to exit the program.\n");
printf(" mode:");
scanf("%s",&mode);//the welcome screen
fflush(stdin);
if(mode[0]==49)//mode1
{
system("cls");
printf("please input the student's name or number:");
scanf("%29s",temp);
fflush(stdin);
if(temp[0]<0)
{
for(num1=0,num3=0;num1<num;num1++)
{
if(!strcmp(temp,students[num1].name))
printf("%s,%s,%s,%d,%s\n",students[num1].name,students[num1].number,students[num1].sex,students[num1].age,students[num1].classes),num3++;
}
if(num3==0) printf("can not find this name\n");
}
else
{
for(num1=0,num3=0;num1<num;num1++)
{
if(!strcmp(temp,students[num1].number))
printf("%s,%s,%s,%d,%s\n",students[num1].name,students[num1].number,students[num1].sex,students[num1].age,students[num1].classes),num3++;
}
if(num3==0) printf("can not find this number\n");
}
system("pause");
}
else if(mode[0]==50)//mode2
{
system("cls");
printf("please input the age range you need tu query:");
scanf("%d %d",&num2,&num3);
getchar();
for(num1=0,num4=0;num1<num;num1++)
{
if(students[num1].age>=num2&&students[num1].age<=num3)
printf("%s,%s,%s,%d,%s\n",students[num1].name,students[num1].number,students[num1].sex,students[num1].age,students[num1].classes),num4++;
}
if(num4==0) printf("can not find a term that meet the crietra\n");
getch();
}
else if(mode[0]==51)//mode3
{
system("cls");
printf("please input the class you want to find:");
scanf("%s",temp);
getchar();
for(num1=0,num3=0;num1<num;num1++)
{
if(!strcmp(temp,students[num1].classes))
printf("%s,%s,%s,%d,%s\n",students[num1].name,students[num1].number,students[num1].sex,students[num1].age,students[num1].classes),num3++;
}
if(num3==0) printf("the class wan not found\n");
system("pause");
}
else if (mode[0]==52)//mode4
{
system("cls");
printf("name,number,sex,age,class\n");
for(num1=0;num1<num;num1++)
{
printf("%s,%s,%s,%d,%s\n",students[num1].name,students[num1].number,students[num1].sex,students[num1].age,students[num1].classes);
}
system("pause");
}
else if(mode[0]=='q') break;//exit
else//input error
{
printf("can not find this mode\n");
system("pause");
}
}
fclose(fp);
return 0;
}