The [a,b]-domination and [a,b]-total Domination of Graphs
- Xiujun Zhang
- Zehui Shao
- Hong Yang
Abstract
A subset $S$ of the vertices of $G = (V, E)$ is an $[a, b]$-set if for every vertex $v$ not in $S$ we have the number of neighbors of $v$ in $S$ is between $a$ and $b$ for non-negative integers $a$ and $b$, that is, every vertex $v$ not in $S$ is adjacent to at least $a$ but not more than $b$ vertices in $S$. The minimum cardinality of an $[a, b]$-set of $G$ is called the $[a, b]$-domination number of $G$. The $[a, b]$-domination problem is to determine the $[a, b]$-domination number of a graph. In this paper, we show that the [2,b]-domination problem is NP-complete for $b$ at least $3$, and the [1,2]-total domination problem is NP-complete. We also determine the [1,2]-total domination and [1,2] domination numbers of toroidal grids with three rows and four rows.