Expert: Prince M. Premnath - 12/4/2007

Question
QUESTION: Hi Prince M. Premnath,

If you would only have time to answer abt 4 to 6 questions on my C classes, you would have helped me a great deal. the first problem is this one: This code is abt getting the grades, sum and average of a number of students. I couldn't understand why it's not compiling. could you check it for me?

#include<stdio.h>
#include<string.h>

int sum(int *s);
int average(int *sum, int n);
void print_info(int *s, int*ave);

int main(void){
   int grade, max,i;
   int    sum, n,m;
   char name[m];
   printf("How many students do you want to enter?");
   scanf("%d",n);
   name[m]= name[n];
   for(i=0;i<name[n];i++);
   printf("enter name of student:");
   scanf("%s",&name[i]);
   printf("%s",name[i]);
   printf("enter the grade:");
   scanf("%d",grade);
   
   sum =0;
   max = grade;
    printf("enter name of student:");
   scanf("%s",&name[i]);
   printf("%s",name[i]);
   printf("\n");
   printf("enter the grade:");
   scanf("%d",grade);
   if(grade>max)
   max = grade;
   sum +=grade;
   sum = int sum(int *s);
   average = int average(int *sum, int n);
   void print_info(int *s, int*ave);
   getchar();
   }
   
   int sum(int *s){
       int u;
       u = *s++;
       return(sum);
       }
       
       int average(int *sum, int n){
       int ave_score;
       ave_score = (*s/n);
       return(ave_score);
       }
       
        void print_info(int *s, int*ave){
         printf("%d",*s);
         printf("%d",*ave);
         }
         
   


ANSWER:     Hi dear Henry I found too many errors,  both logical and syntactical !! I suggest you to learn the basic constructs of C programming Language ( arrays , pointers , loops and so on ..) because i spot most errors with this constructs !

If i intend to correct the errors in this program , then sure you will say "Who's programme is this ?" but i don't like to dis appoint you ! if you wish , specify your question clearly , let me help you out in writing code !
For assistance just post a follow up ( Feel free )

With Thanks and Regards!
Prince M. Premnath



---------- FOLLOW-UP ----------

QUESTION: Hi,

Thanks alot. Exactly my problem. I just don't know where my errors are coming from. Now, i think i have an idea. Vould you  write out the code but a bit clearer. such that i can study it and understand. I actually have been grappling with how to use functions, pointers and arrays correclty plus loops. But i am certain that with this problem, all that could be answered. Please, when using any function with pointers as parameters , kindly state why . I know already why but got more confused why it's not working for me. Thanks alot. I will be expecting your own simplified version of the programme.Please, explain more on the logical errors of this programme when writing yours using comments.

Answer
Hi dear Henry !

here im presenting you a simple program developed using the help of structures , you can also develop solution for this prob using arrays too instead of using structures ..

#include<stdio.h>
#include<string.h>
/* define student record */
struct student
{
  char name[30];
  int marks[5]; /* for 5 subjects */
  float avg , total;
  int grade;
};

void main()
{
  int n ; /* how many students */
  struct student stud[100];
  /* you can store information about a maximum of 100 students*/
  int i , j;
  float temp;
  printf("Enter how many students :");
  scanf("%d" , &n);
  for( i = 0 ; i < n ; i++)
  {
     printf("Enter student name :");
     scanf("%s" , stud[i].name);
     printf("Enter student grade :");
     scanf("%d" , &stud[i].grade);
     printf("Enter 5 subject mark :");
     for(j = 0 ; j<5 ; j++)
        scanf("%d"  , &stud[i].marks[j]);
      /* calculate total and average for that particular student */
      temp = 0;
      for( j = 0 ; j < 5 ; j++)
        temp += stud[i].marks[j];
      stud[i].total = (float)temp;
      stud[i].avg = (float)temp/5.0;
  }
  printf("Print student info :\n");

  for( i = 0 ; i < n ; i++)
  {
     printf(" student name :%s\n" , stud[i].name);
     printf(" student grade :%d\n" , stud[i].grade);
     printf("5 subject mark :");
     for(j = 0 ; j <5 ; j++)
        printf(" %d"  , stud[i].marks[j]);
     printf("Total = %f\n" , stud[i].total);
     printf("Average %f\n" , stud[i].avg);
   }
}

if you spot any bugs with this prog kindly report it to me , feel free to post follow ups

Thanks and Regards !
Prince M. Premnath