Memory leaks and how to prevent them

main.c

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

void random_array(int* arr, int n) {
    srand(0);
    int i;
    for (i = 0; i < n; i++) {
        arr[i] = rand() % 100;
    }
}

int main(int argc, char* argv[]) {
    int* arr = malloc(sizeof(int) * 15);
    int* arr_copy = arr;
    random_array(arr, 15);
    int i;
    for (i = 0; i < 15; i++) {
        printf("%d\n", *(arr_copy++));
    }
    arr_copy = NULL;
    free(arr);
    return 0;
}