Memory-Adjustable Navigation Piles with Applications to Sorting and Convex Hulls

We consider space-bounded computations on a random-access machine, where the input is given read-only medium, output to be produced write-only sequential-access and available workspace allows random reads writes but of limited capacity. The length N elements, by computation, capacity O ( S ) bits for some predetermined parameter ≥ lg . present state-of-the-art priority queue—called an adjustable navigation pile —for this restricted model. This queue supports M inimum in (1) time, C onstruct E xtract - min / + time any can further augmented deal with batch at most elements specified range values allow I nsert (activate) or (deactivate) element among these such that take show how use our data structure sort compute convex hull points Euclidean plane 2 Following known lower bound space-time product branching program finding unique both sorting convex-hull algorithms are optimal. has turned out useful when designing other space-efficient algorithms, we expect it will find its way yet applications.