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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _sample_without_replacement(n, r, out):
 """ Main body of `sample_without_replacement`. To be complied as a ufunc by guvectorize of Numba. """

    k = r.shape[0]

    # Logic taken from random.sample in the standard library
    pool = np.arange(n)
    for j in range(k):
        idx = int(np.floor(r[j] * (n-j)))  # np.floor returns a float
        out[j] = pool[idx]
        pool[idx] = pool[n-j-1]