Time-Space Trade-off Algorithms for Triangulating a Simple Polygon

Abstract

An s-workspace algorithm is an algorithm that has read-only access to the values of the input, write-only access to the output, and only uses O(s) additional words of space. We present a randomized s-workspace algorithm for triangulating a simple polygon P of n vertices that runs in O(n 2 /s + n log n log 5 (n/s)) expected time using O(s) variables, for any s ≤ n. In particular, when s ≤ n log n log 5 log n the algorithm runs in O(n 2 /s) expected time.