not working
int **split_array(const int *s, int length) {
    int **arr[2];
    int numEven, numOdd;

    numOdd = length / 2;
    if (length % 2 == 0) {
        numEven = length / 2;
    } else {
        numEven = (length / 2) + 1;
    }

    arr[0] = malloc(sizeof(int) * numEven);
    arr[1] = malloc(sizeof(int) * numOdd);

    for (int i = 0; i < length; i = i + 2) {
        arr[0][i] = s[i];
    }

    for (int j = 0; j < length; j = j + 2) {
        arr[1][j] = s[j];
    }

    return arr;
}