A Coloring Algorithm for Interval Graphs

We devise a new optimal on-line coloring algorithm for interval graphs. Then we exhibit how it can be used to the construction of a polynomial time approximation strategy for the NP-hard dynamic storage allocation problem. Previously Chrobak, Slusarek, and Woodall applied the suboptimal greedy coloring (first fit) to the analysis of a certain allocation strategy. Due to that analysis (only partially carried out) the performance ratio of their allocation algorithm lies within [4.45, 40]. The new strategy decribed here achieves the performance ratio of 3.