is_pseudographical¶
- is_pseudographical(sequence)[source]¶
Returns True if some pseudograph can realize the sequence.
Every nonnegative integer sequence with an even sum is pseudographical (see [1]).
- Parameters
- sequencelist or iterable container
A sequence of integer node degrees
- Returns
- validbool
True if the sequence is a pseudographic degree sequence and False if not.
Notes
The worst-case run time is \(O(n)\) where n is the length of the sequence.
References
- 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).