Using multiple inverted trees for parallel updating of graph properties. Technical report

Technical Report · Wed May 01 04:00:00 EDT 1985

OSTI ID:5520387

Ramakrishnan, I V

Fast parallel algorithms are presented for updating the distance matrix, shortest paths for all pairs and biconnected components for an undirected graph and the topological ordering of vertices of a directed acyclic graph when an incremental change has been made to the graph. The kinds of changes that are considered here include insertion of a vertex of insertion and deletion of an edge or a change in the weight of an edge. The machine model used is a parallel random-access machine which allows simultaneous reads but prohibits simultaneous writes into the same memory location. The algorithms described in this paper require O(log n) time and use O(N-cubed) processors. These algorithms are efficient when compared to previously known 0(log-squared of n) time start-over algorithms for initial computation of the above-mentioned properties of graphs. The previous solution is maintained in multiple inverted trees (a rooted tree where a child node points toward its parent) and after a minor change the new solution is rapidly recomputed from these trees

• Research Organization: Maryland Univ., College Park (USA). Dept. of Computer Science
• OSTI ID: 5520387
• Report Number(s): AD-A-166058/8/XAB; CAR-TR-124
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
990200* -- Mathematics & Computers
ALGORITHMS
COMPUTER GRAPHICS
GRAPHS
MATHEMATICAL LOGIC
MATRICES
PARALLEL PROCESSING
PROGRAMMING