Question

Question 4: C Programming (15 points) Create a program that asks the user for an integer number representing the number of students in a classroom. Your program will then malloc an array of struct students having the same number of cells as input by the user's integer number. The student struct will have only two fields: student name and gpa. Your program then opens a CSV file

Answer 1

• I have pasted the fully tested code below
• I have also pasted example GPA.csv which assumes every line contains one tuple like in the format(name,gpa) without any spaces
• It skips the lines and prints error on screen
• At the end of program it prints the number of lines read and entries filled in array and average GPA
• In case of any doubts just comment down
• I have also pasted sample run of program

------------------Sample Run------------------

desperado:37.file-real-c -> r Number of students: 3 Line 3: GPA (-2.500000) can not be negative Read 4 line (s) Filled 3 entr(y/ies) in array Average GPA is 2.550000

------------------GPA.CSV------------------

(John,1.5)
(Rambo,2.5)
(Student,3.6)

------------------STUDENT.C------------------

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#define MAX_SIZE 100

typedef struct student {

char name[100];

double gpa;

}student;

// void writeToFile(int size, employee Employees[]){

// FILE *fp;

// fp = fopen("employee.txt","w");

// fprintf(fp,"%d\n",size);

// for (int i = 0; i < size; ++i)

// {

// fprintf(fp,"%s\n%s\n",Employees[i].name,Employees[i].city);

// }

// fclose(fp);

// printf("Data successfully written to file employee.txt\n");

// }

// void readFromFile(int *s, employee Employees[]){

// int size = *s;

// FILE *fp;

// fp = fopen("employee.txt","r");

// fscanf(fp,"%d", &size);

// for (int i = 0; i < size; ++i)

// {

// fscanf(fp,"%[^\n]", Employees[i].name);

// fscanf(fp,"%[^\n]", Employees[i].city);

// }

// fclose(fp);

// *s = size;

// printf("Data successfully read from file employee.txt\n");

// }

// void modifyLastEmployee(int size, employee Employees[]){

// strncpy(Employees[size-1].city, "Kilburn", sizeof(Employees[size-1].city));

// }

// void printEmployees(int size, employee Employees[]){

// printf("%15s%15s\n","Name","City");

// for (int i = 0; i < size; ++i){

// printf("%15s%15s\n",Employees[i].name,Employees[i].city);

// }

// }

// void populateEmployees(int *size, employee Employees[]){

// int i = *size;

// strncpy(Employees[i].name, "H. Baker", sizeof(Employees[i].name));

// strncpy(Employees[i].city, "Orange", sizeof(Employees[i].city));

// i++;

// strncpy(Employees[i].name, "D. Rosso", sizeof(Employees[i].name));

// strncpy(Employees[i].city, "Madison", sizeof(Employees[i].city));

// i++;

// strncpy(Employees[i].name, "K. Tims", sizeof(Employees[i].name));

// strncpy(Employees[i].city, "Millburn", sizeof(Employees[i].city));

// i++;

// strncpy(Employees[i].name, "B. Williams", sizeof(Employees[i].name));

// strncpy(Employees[i].city, "Brooklyn", sizeof(Employees[i].city));

// i++;

// *size = i;

// }

// void addEmployees(int *s, employee Employees[]){

// int n;

// int size = *s;

// printf("Number of employees to add(MAX=%d): ",MAX_SIZE-size);

// scanf("%d",&n);

// if(size+n>MAX_SIZE){

// printf("Maximum number of employees you can add is %d\n",MAX_SIZE-size);

// return;

// }

// for (int i = 0; i < n; ++i){

// printf("Employee Name: ");

// scanf(" %[^\n]",Employees[size].name);

// printf("Employee City: ");

// scanf(" %[^\n]",Employees[size++].city);

// }

// *s = size;

// }

int main(){

//Ask for number of students

int n;

printf("Number of students: ");

scanf("%d",&n);

//Declaring array of size 'n'

student Students[n];

//Open file "GPA.CSV"

FILE *fp;

fp = fopen("GPA.CSV","r");

//If file does not exist then exit

if(!fp){

printf("File GPA.CSV does not exist.\n");

return 0;

}

// Read file line by line

char line[100];

int line_number = 1;

int i = 0;

double gpa_sum = 0;

while (fgets(line, 100, fp) != NULL && i<n){

// subtracting 1 to exclude new line symbol

int len = (unsigned)strlen(line);

if(line[len-1]=='\n'){

len--;

}

int j = 0;

if(line[0]=='(' && line[len-1]==')'){

int j = len-2;

for(j;j>1;j--){

if(line[j]==','){

break;

}

}

if(j==1 || j==len-2){

printf("Line %d not formatted properly\n", line_number);

}else{

char num[100];

for(int k=j+1,ki=0;k<len-1;k++,ki++){

num[ki] = line[k];

}

double g = atof(num);

if(g>=0){

gpa_sum += g;

Students[i].gpa = g;

for(int k=1;k<j;k++){

Students[i].name[k-1] = line[k];

}

i++;

}else{

printf("Skipping Line %d: GPA(%lf) can not be negative\n", line_number,g);

}

}

}else{

printf("Line %d not formatted properly\n", line_number);

}

line_number++;

}

printf("Read %d line(s)\n", line_number-1);

printf("Filled %d entr(y/ies) in array\n", i);

printf("Average GPA is %lf\n", gpa_sum/(i));

fclose(fp);

return 0;

}