## Time-Space Lower Bounds for Directed s-t Connectivity on JAG Models (Extended Abstract) (1993)

Citations: | 11 - 2 self |

### BibTeX

@MISC{Barnes93time-spacelower,

author = {Greg Barnes and Jeff A. Edmonds},

title = {Time-Space Lower Bounds for Directed s-t Connectivity on JAG Models (Extended Abstract)},

year = {1993}

}

### Years of Citing Articles

### OpenURL

### Abstract

Directed s-t connectivity is the problem of detecting whether there is a path from a distinguished vertex s to a distinguished vertex t in a directed graph. We prove time-space lower bounds of ST = \Omega\Gamma n 2 = log n) and S 1=2 T = \Omega\Gamma mn 1=2 ) for Cook and Rackoff's JAG model [8], where n is the number of vertices and m the number of edges in the input graph, and S is the space and T the time used by the JAG. We also prove a timespace lower bound of S 1=3 T = \Omega\Gamma m 2=3 n 2=3 ) on the more powerful node-named JAG model of Poon [13]. These bounds approach the known upper bound of T = O(m) when S = \Theta(n log n).