store a table in dynamic array and then change the size of array dynamically to store more numbers

 #include <stdio.h>

#include <stdlib.h>

int main()

{

    int *ptr;

    ptr = (int *)malloc(10 * sizeof(int));

   

    printf("The multiplication table of 7 is:\n");

    for (int i = 0; i < 10; i++)

    {

        ptr[i]=7*i;

        printf("7 X %d = %d\n",i+1,ptr[i]);

    }

   ptr = realloc(ptr, 15 * sizeof(int));

   printf("\nThe multiplication table of 7 till 15 is:\n");

    for (int i = 0; i < 15; i++)

    {

        ptr[i]=7*i;

        printf("7 X %d = %d\n",i+1,ptr[i]);

    }

    free(ptr);

    return 0;

}