Student Marks Using Dynamic Memory in C

Summary: This program allocates memory at runtime using malloc() to store marks of students. It calculates and displays the average of those marks, and properly frees the memory afterwards.

#include <stdio.h>
#include <stdlib.h>

int main() {
    int n;
    float *marks, sum = 0;

    printf("Enter number of students: ");
    scanf("%d", &n);

    marks = (float *) malloc(n * sizeof(float));
    if (marks == NULL) {
        printf("Memory allocation failed.\n");
        return 1;
    }

    printf("Enter marks: ");
    for (int i = 0; i < n; i++) {
        scanf("%f", marks + i);
        sum += *(marks + i);
    }

    printf("Average marks = %.2f\n", sum / n);

    free(marks);
    return 0;
}

Explanation:

Memory Allocation:
The program uses malloc() to dynamically allocate memory for storing student marks. This is necessary when the number of students is not known at compile time.

Pointer Arithmetic:
The program accesses elements using pointer arithmetic like *(marks + i) instead of array indexing.

Sum and Average:
As each mark is entered, it is immediately added to sum. The average is calculated by dividing the total sum by the number of students.

Memory Deallocation:
After usage, the memory is freed using free() to avoid memory leaks.