C Language training course, C Language student achievement management system, for your reference, the specific content is as follows

#include<stdio.h>
#include<string.h>
#include<math.h>
struct student
 {
 int num;
 char name[20];
 float pingshi;
 float shiyan;
 float kaoshi;
 double zongping;
 }stu[4];
void main()
{
 void a();
 void b();
 void c();
 void d();
 void e();
 int n;
 while(n!=6)
 { printf("\t University computer basic grade management system \n");
 printf("1 Input: 1 Basic computer scores of students in one class \n");
 printf("2 : Displays all achievement records \n");
 printf("3 : Calculate and output the mean score, mean square error \n");
 printf("4 : Output grades and rankings \n");
 printf("5 : The result is stored in the file chengji.txt\n");
 printf("6 : Quit the system \n");
 printf(" Enter option code :");
 scanf("%d",&n);
 switch(n)
 {
 case 1:a();break;
 case 2:b();break;
 case 3:c();break;
 case 4:d();break;
 case 5:e();break;
 case 6:printf("\n******************* Thanks for using! *******************\n");break;
 break;
 }
 }
getchar();
}
/*  The child   letter   The number */
void a() /*  The input 1 Student records of each class */

{
 int i;

 for(i=0;i<4;i++)

 {

 printf(" Please enter your student number   The name   grades   The experimental results   Examination results: ");

 scanf("%d%s%f%f%f",&stu[i].num,stu[i].name,&stu[i].pingshi,&stu[i].shiyan,&stu[i].kaoshi);

 }for(i=0;i<4;i++)
stu[i].zongping=0.1*stu[i].pingshi+0.3*stu[i].shiyan+0.6*stu[i].kaoshi;
}
void b()/*  Display all records */

{
 int i;

 printf(" Student id   The name   grades   The experimental results   Test scores   Overall performance \n");

 for(i=0;i<4;i++)

 printf("%d%14.2s%14.2f%14.2f%14.2f%14.2f\n",stu[i].num,stu[i].name,stu[i].pingshi,stu[i].shiyan,stu[i].kaoshi,stu[i].zongping);

}

void c()/*  Figure out the class average and show the mean square error */
{
 int a[4]={0,1,2,3};
 int i,j;
 double total=0,pfc=0,bzc=0;
 double ave;
 for(i=0;i<4;i++)
 {
 total=total+stu[i].zongping;
 }
 ave=total/4.0;
 printf(" The overall average score is %f\n",ave);
 for(i=0;i<4;i++)
 {
 pfc=pow((stu[i].zongping-ave),2)/4;
 }
 bzc=sqrt(pfc);
 printf("\n (yi - (mxi + b)) is %f\n",pfc);
 printf("\n The standard deviation is %f\n",bzc);
}
void d()

{
 int a[4]={0,1,2,3};
 int i,j,temp;
 for(j=0;j<3;j++)
 {
 for(i=0;i<3-j;i++)
 if(stu[a[i]].zongping>stu[a[i+1]].zongping)
 {
 temp=a[i];a[i]=a[i+1];
 a[i+1]=temp;

 }
 }

 printf(" The order :\n");

 printf(" Student id   The name   Overall performance \n");

 for(i=0;i<4;i++)

 printf("%d%10.2s%15.2f\n",stu[a[i]].num,stu[a[i]].name,stu[a[i]].zongping);

 printf("\n");

}

void e()
{int i;
FILE *fp;
fp=fopen("chengji.txt","w");

 fprintf(fp," Student id   The name   grades   The experimental results   Test scores   Overall performance \n");

 for(i=0;i<4;i++)

 fprintf(fp,"%d%14.2s%14.2f%14.2f%14.2f%14.2f\n",stu[i].num,stu[i].name,stu[i].pingshi,stu[i].shiyan,stu[i].kaoshi,stu[i].zongping);

printf("\n\n******************* Congratulations, save complete! *******************\n\n");
}

Simple recording.

For more information, please pay attention to the topic management System Development.