منابع مشابه
Polyhedral studies on the convex recoloring
A coloring of the vertices of a graph G is convex if, for each assigned color d, the vertices with color d induce a connected subgraph of G. We address the convex recoloring problem, defined as follows. Given a graph G and a coloring of its vertices, recolor a minimum number of vertices of G, so that the resulting coloring is convex. This problem is known to be NP-hard even when G is a path. We...
متن کاملConvex recoloring of leaf-colored trees
A coloring of the leaves of a tree T is called convex, if it is possible to give each internal node a color, such that for each color, the set of nodes with that color forms a subtree of T . Motivated by a problem from phylogenetic reconstruction, we study the problem, when given a tree with a coloring of its leaves, to recolor as few as possible leaves to obtain a convex coloring. We present f...
متن کاملConvex Recoloring Revisited: Complexity and Exact Algorithms
We take a new look at the convex path recoloring (CPR), convex tree recoloring (CTR), and convex leaf recoloring (CLR) problems through the eyes of the independent set problem. This connection allows us to give a complete characterization of the complexity of all these problems in terms of the number of occurrences of each color in the input instance, and consequently, to present simpler NP-har...
متن کاملRecoloring Directed Graphs
Let G be a directed graph and k a positive integer. We define the k-color graph of G (Dk(G) for short) as the directed graph having all k-colorings of G as node set, and where two k-colorings β and φ are joined by a directed edge β → φ if φ is obtained from β by choosing a vertex v and recoloring v so that its color is different from the colors of all its out-neighbors. We investigate reachabil...
متن کاملThe Edge-Recoloring Cost of Paths and Cycles in Edge-Colored Graphs and Digraphs
We introduce a number of problems regarding edge-color modifications in edge-colored graphs and digraphs. Consider a property π, a c-edge-colored graph G not satisfying π, and an edge-recoloring cost matrix R = [rij ]c×c where rij ≥ 0 denotes the cost of changing color i of edge e to color j. Basically, in this kind of problem the idea is to change the colors of one or more edges of G in order ...
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ژورنال
عنوان ژورنال: Discrete Applied Mathematics
سال: 2014
ISSN: 0166-218X
DOI: 10.1016/j.dam.2013.02.034