Maximum Independent Set for Interval Graphs and Trees in Space Efficient Models
نویسندگان
چکیده
Space efficient algorithms for the maximum independent set problem for interval graphs and trees are presented in this paper. For a given set of n intervals on a real line, we can compute the maximum independent set in O( 2 s + n log s) time using O(s) extra-space. The lower bound of the time × space product for this problem is Ω(n2− ), where = O(1/ √ log n). We also propose an (1+ 1 ) approximation algorithm for this problem that executes O( 1 ) passes over the read-only input tape and uses O(k) extra space, where k is the size of the reported answers. For trees with n nodes, our proposed 53 -approximation algorithm runs in O(n) time using O(1) extra-space.
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