Solving the MCQP, MLT, and MMLT problems and computing weakly and strongly stable quickest paths

Abstract

The quickest path problem consists of finding a path in a directed network to transmit a given amount $$\sigma $$ of items from a source node to a sink node with minimal transmission time, where the transmission time depends on the traversal times $$\tau $$ and the capacities u of the arcs. We suppose that there exist more than one quickest path and finds a quickest path with a special property. In this paper, first, some algorithms to find a quickest path with minimum capacity, minimum lead time, and min-max arc lead time are presented, which runs in $$O(r(m+n \log n))$$ and $$ O((r(m+n \log n))\log r') $$ time, where r and $$ r' $$ are the number of distinct capacity and lead time values and m and n are the number of arcs and nodes in the given network. Then, we suppose that values $$\sigma , \tau $$ and u change to $$\sigma ', \tau '$$ , and $$u'$$ . The purpose is to find a quickest path such that it has the minimum transmission time value among all quickest paths, by changing $$\sigma $$ to $$\sigma '$$ , $$\tau $$ to $$\tau '$$ , or u to $$u'$$ . We show that some of these problems are solved in strongly polynomial time and the others remain as open problems.