Eulerian circuit | Eulerian tour

An Eulerian cycle, also called an Eulerian circuit, Euler circuit, Eulerian tour, or Euler tour, is a trail which starts and ends at the same graph vertex. In other words, it is a graph cycle which uses each graph edge exactly once. For technical reasons, Eulerian cycles are mathematically easier to study than are Hamiltonian cycles. An Eulerian cycle for the octahedral graph is illustrated above. As a generalization of the Königsberg bridge problem, Euler showed (without proof) that a connected graph has an Eulerian cycle iff it has no graph vertices of odd degree.

Chinese postman problem | Eulerian graph | Eulerian path | Hamiltonian cycle | unicursal circuit