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Decomposition of balanced matrices. (English) Zbl 1023.05025
Summary: A $$(0,1)$$ matrix is balanced if it does not contain a square submatrix of odd order with two ones per row and per column. We show that a balanced $$(0,1)$$ matrix is either totally unimodular or its bipartite representation has a cutset consisting of two adjacent nodes and some of their neighbors. This result yields a polytime recognition algorithm for balancedness. To prove the result, we first prove a decomposition theorem for balanced $$(0,1)$$ matrices that are not strongly balanced.

##### MSC:
 05B20 Combinatorial aspects of matrices (incidence, Hadamard, etc.)
##### Keywords:
balanced $$(0,1)$$ matrix; recognition algorithm
Full Text:
##### References:
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