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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 _map_tril_1d_on_2d(indices, dims):
 """Map 1d indices on lower triangular matrix in 2d. """


    N = (dims * dims - dims) / 2

    m = np.ceil(np.sqrt(2 * N))
    c = m - np.round(np.sqrt(2 * (N - indices))) - 1
    r = np.mod(indices + (c + 1) * (c + 2) / 2 - 1, m) + 1

    return np.array([r, c], dtype=np.int64)