The 14 different <a href="https://en.wikipedia.org/wiki/Acyclic_orientation" class="extiw" title="en:Acyclic orientation">acyclic orientations</a> of a 4-vertex <a href="https://en.wikipedia.org/wiki/Cycle_graph" class="extiw" title="en:Cycle graph">cycle graph</a>, assignments of a direction to each cycle edge that make the resulting directed graph <a href="https://en.wikipedia.org/wiki/Directed_acyclic_graph" class="extiw" title="en:Directed acyclic graph">acyclic</a>. Two orientations are shown as adjacent when they differ in the direction of a single edge.
<a href="//commons.wikimedia.org/wiki/User:David_Eppstein" class="mw-redirect" title="User:David Eppstein">David Eppstein</a>
<span class="int-own-work" lang="en">Own work</span>