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Returns True if some pseudograph can realize the sequence.

Every nonnegative integer sequence with an even sum is pseudographical (see [1]).

Parameters:sequence (list or iterable container) – A sequence of integer node degrees
Returns:valid – True if the sequence is a pseudographic degree sequence and False if not.
Return type:bool


The worst-case run time is O(n) where n is the length of the sequence.


[1]F. Boesch and F. Harary. “Line removal algorithms for graphs and their degree lists”, IEEE Trans. Circuits and Systems, CAS-23(12), pp. 778-782 (1976).