In the last ten years, many simple combinatorial algorithms have been designed that compute all-pairs approximate shortest paths (APASP) for undirected graphs. The objective for designing an algorithm for
APASP problem is to achieve sub-cubic preprocessing time and/or sub-quadratic space at the expense of introducing some additive and/or
multiplicative error in the shortest path.
The talk will address two important algorithms for APASP, and mention a few open problems in the area of all-pairs approximate shortest paths.
The source papers :
Paper 1:
D. Dor, S. Halperin, and U. Zwick
"All pairs almost shortest paths"
SIAM Journal on Computing, 29:1740--1759, 2000
Paper 2:
M. Thorup and U. Zwick
"Approximate distance oracles"
STOC Proceedings 2001, pages 183--192