def flattened_indices_from_row_col_indices(row_indices, col_indices, num_cols):
    'Get the index in a flattened array given row and column indices.'
    return ((row_indices * num_cols) + col_indices)
Get the index in a flattened array given row and column indices.
def flattened_indices_from_row_col_indices(row_indices, col_indices, num_cols):
    
    return ((row_indices * num_cols) + col_indices)