Given two integers $\ell$ and $p$ as well as $\ell$ graph classes $\mathcal{H}_1,\ldots,\mathcal{H}_\ell$, the problems $\mathsf{GraphPart}(\mathcal{H}_1, \ldots, \mathcal{H}_\ell,p)$, $\mathsf{VertPart}(\mathcal{H}_1, \ldots, \mathcal{H}_\ell)$, and $\mathsf{EdgePart}(\mathcal{H}_1, \ldots, \mathcal{H}_\ell)$ ask, given graph $G$ as input, whether $V(G)$, $V(G)$, $E(G)$ respectively can be partitioned into $\ell$ sets $S_1, \ldots, S_\ell$ such that, for each $i$ between $1$ and $\ell$, $G[S_i] \in \mathcal{H}_i$, $G[S_i] \in \mathcal{H}_i$, $(V(G),S_i) \in \mathcal{H}_i$ respectively. Moreover in $\mathsf{GraphPart}(\mathcal{H}_1, \ldots, \mathcal{H}_\ell,p)$, we request that the number of edges with endpoints in different sets of the partition is bounded by $p$. We show that if there exist dynamic programming tree-decomposition-based algorithms for recognizing the graph classes $\mathcal{H}_i$, for each $i$, then we can constructively create a dynamic programming tree-decomposition-based algorithms for $\mathsf{GraphPart}(\mathcal{H}_1, \ldots, \mathcal{H}_\ell,p)$, $\mathsf{VertPart}(\mathcal{H}_1, \ldots, \mathcal{H}_\ell)$, and $\mathsf{EdgePart}(\mathcal{H}_1, \ldots, \mathcal{H}_\ell)$. We show that, in some known cases, the obtained running times are comparable to those of the best know algorithms.
翻译:给定两个整数$\ell$和$p$,以及$\ell$个图类$\mathcal{H}_1,\ldots,\mathcal{H}_\ell$,问题$\mathsf{GraphPart}(\mathcal{H}_1, \ldots, \mathcal{H}_\ell,p)$、$\mathsf{VertPart}(\mathcal{H}_1, \ldots, \mathcal{H}_\ell)$和$\mathsf{EdgePart}(\mathcal{H}_1, \ldots, \mathcal{H}_\ell)$分别询问:对于输入图$G$,能否将$V(G)$、$V(G)$、$E(G)$划分为$\ell$个集合$S_1, \ldots, S_\ell$,使得对于每个$i$($1 \leq i \leq \ell$),分别有$G[S_i] \in \mathcal{H}_i$、$G[S_i] \in \mathcal{H}_i$、$(V(G),S_i) \in \mathcal{H}_i$。此外,在$\mathsf{GraphPart}(\mathcal{H}_1, \ldots, \mathcal{H}_\ell,p)$中,我们要求不同划分集合之间端点相连的边数不超过$p$。我们证明:若对每个$i$,存在基于动态规划树分解的算法可识别图类$\mathcal{H}_i$,则我们可构造性地创建基于动态规划树分解的算法,分别求解$\mathsf{GraphPart}(\mathcal{H}_1, \ldots, \mathcal{H}_\ell,p)$、$\mathsf{VertPart}(\mathcal{H}_1, \ldots, \mathcal{H}_\ell)$和$\mathsf{EdgePart}(\mathcal{H}_1, \ldots, \mathcal{H}_\ell)$。我们进一步表明,在某些已知情形下,所得运行时间可与已知最优算法相媲美。