2 problems

Let $G$ be an $r$-regular graph, meaning every vertex of $G$ has degree $r$, with $r\geq 3$. A zero-sum $5$-flow is a zero-sum flow whose integer edge values satisfy…

Let $G$ be a finite undirected graph. A zero-sum flow assigns a nonzero integer to each edge so that the sum of the assignments on all edges incident with every vertex is zero. A z…