Files2

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char*change_binary(int num)
{
    int i, k = 0, temp = num, cnt = 0, *arr = NULL; char *str = NULL;
    while (num != 0)
    {
        temp = num;
        temp %= 2;
        str = (char *)realloc(str, sizeof(char)*(k + 1));
        *(str + k) = temp + '0';
        k++;
        num /= 2;
    }
    *(str + k) = NULL;

    puts(str);
    return str;
}
void main()
{
    FILE *f1, *f2; int i, j = 0, k = 0, *arr = NULL, *intarr = NULL, temp = -1; char *newarr = NULL, tempr[5];
    fopen_s(&f1, "data2.txt", "rt");
    fopen_s(&f2, "res1.txt", "w");
    if (f1 == NULL)
        exit(1);
    for (i = 0; temp != 0; i++)
    {
        arr = (int *)realloc(arr, sizeof(int)*(i + 1));
        if (arr == NULL)
            exit(1);
        fscanf_s(f1, "%d", &temp);
        *(arr + i) = temp;
    }
    if (f1 == NULL)
        exit(1);
    for (i = 0; i < 16; i++)
    {
        if (arr[i] % 2 == 0)
            fprintf_s(f2, "%-3d", arr[i]);
        else
        {
            int num2, num = arr[i];
            num2 = arr[i];
            k = 0;
            while (num != 0)
            {
                temp = num;
                temp %= 2;
                newarr = (char *)realloc(newarr, sizeof(char)*(k + 1));
                intarr = (int *)realloc(intarr, sizeof(int)*(k + 1));
                *(newarr + k) = temp + '0';
                tempr[k] = *(newarr + k);
                k++;
                num /= 2;

            }
            *(newarr + k) = NULL;

            printf("The number in dec is :  %d \n and in binary is: \n", num2);
            printf("%b", num2);
            puts(newarr);
        }

    }

    for (i = 0; i < k; i++)
    {
        printf("%-3d", *(newarr + i));
    }
}