0$ there is a vertex $u$ adjacent to $v$ with $f(u)>0$.The weight of $f$ is the sum $f(V)=\sum_{v\in V}f(v)$. The minimum weight of a TDRDF on $G$ is the total double Romandomination number of $G$. In this paper, we give a linear algorithm to compute thetotal double Roman domination number of agiven tree.]]>