On the Algorithmic Complexity of Roman $$\{2\}$$-Domination (Italian Domination)

A Roman f2g-dominating function (R2DF) f : V f0; 1; 2g of a graph G ¼ ðV; EÞ has the property that for every vertexv 2 V with f ðvÞ ¼ 0 either there is a vertex u 2 NðvÞ with f ðuÞ ¼ 2 or there ar