Question

***************C PROGRAMMING ONLY*************

• Demonstrate the ability to create an array on the stack
• Demonstrate the ability to create an array on the heap allowing user to choose the number of values to store.
• Demonstrate the ability to store an array of Struct values on both the stack and the heap.

Program Specifications:

1. Create a struct with at least 3 fields - any struct you want but explain it in your comments in the code. Populate at least 10 elements in an array of elements of this struct type with a limit of 1000 elements.

2. Create an array on the heap to store the same number of populated elements from the stack array.

3. Copy the values from the stack array into the dynamic array.

The program will output the contents from each array, one at a time.

** You can have a menu system if you wish but it is not a requirement **

4. Finally, create a BIN file to store the contents of the array on the heap.

Answer 1

// C program to create array of structures on Stack and Heap

#include <stdio.h>

#include <stdlib.h>

#include <time.h>

// struct representing a student

typedef struct

{

               int id; // id of student

               int score; // score of student

               char grade; // grade of student

}student;

int main(void) {

               srand(time(NULL));

               const int MAXSIZE = 1000;

               student students_stack[MAXSIZE];

               int numElements = 10;

               int i;

               // loop to populate 10 elements in array in stack

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

               {

                              students_stack[i].id = i+1;

                              students_stack[i].score = rand()%101;

                              if(students_stack[i].score >=90)

                                             students_stack[i].grade = 'A';

                              else if(students_stack[i].score >=80)

                                             students_stack[i].grade = 'B';

                              else if(students_stack[i].score >=70)

                                             students_stack[i].grade = 'C';

                              else if(students_stack[i].score >=50)

                                             students_stack[i].grade = 'D';

                              else

                                             students_stack[i].grade = 'F';

               }

               // Create an array on the heap to store the same number of populated elements from the stack array.

               student *students_heap = (student*)malloc(numElements*sizeof(student));

               // if memory not allocated, exit

               if(students_heap == NULL)

               {

                              printf("\n Memory not allocated");

                              return EXIT_FAILURE;

               }

               //Copy the values from the stack array into the dynamic array.

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

               {

                              students_heap[i].id = students_stack[i].id;

                              students_heap[i].score = students_stack[i].score;

                              students_heap[i].grade = students_stack[i].grade;

               }

               // print the elements from both the array

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

               {

                              printf("\n Stack : ");

                              printf(" ID : %d Score : %d Grade : %c",students_stack[i].id,students_stack[i].score,students_stack[i].grade);

                              printf("\n Heap : ");

                              printf(" ID : %d Score : %d Grade : %c",students_heap[i].id,students_heap[i].score,students_heap[i].grade);

               }

               // write contents of heap to binary file

               FILE *filePtr = fopen("students.bin","w");

               if(filePtr == NULL)

               {

                              printf("Unable to open file");

                              return EXIT_FAILURE;

               }

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

               {

                              if(i != numElements-1)

                                             fprintf(filePtr,"%d %d %c\n",students_heap[i].id,students_heap[i].score,students_heap[i].grade);

                              else

                                             fprintf(filePtr,"%d %d %c",students_heap[i].id,students_heap[i].score,students_heap[i].grade);

               }

               fclose(filePtr);

               return EXIT_SUCCESS;

}

//end of program

Output: