The inner loop of createMatrixAdjacencyInverse() has an error: it checks (*it)->isIsolated() (the outer iterator) instead of (*it1)->isIsolated() (the inner iterator). This means isolated vertices are never correctly skipped in the inner loop, potentially causing isSingular to be computed incorrectly.
The inner loop of createMatrixAdjacencyInverse() has an error: it checks (*it)->isIsolated() (the outer iterator) instead of (*it1)->isIsolated() (the inner iterator). This means isolated vertices are never correctly skipped in the inner loop, potentially causing isSingular to be computed incorrectly.