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Critical

apropos

The Greedy Algorithm,on ‘independence systems’ (as, for example, in the case of the Algorithm of Kruskal, the system of spanning forests of a graph). However, the strategy used is rather short-sighted: we always choose the element which seems best at the moment (that is, of all the admissible elements, we choose the ele

粉笔

Flows, the connections are given? Such a network might be a model for a system of pipelines or a water supply system or for a system of roads. The theory of flows is one of the most important parts of Combinatorial Optimization; it has various applications as well in Mathematics as in other fields. The bo

largesse

ALLEY

圆木可阻碍

Circulations,various applications of this theory. The present chapter treats generalizations of the flows we worked with so far. For example, it occurs quite often that, for some network, there are lower bounds on the capacities of the edges or a cost function on the edges given as well. To solve this kind of pr

Injunction

Synthesis of Networks,For given conditions on the flow, construct a network (with as little effort as possible) on which such a flow would be possible. On the one hand, we consider the case where all edges can be built with the same cost and we are looking for an undirected network with lower bounds on the maximal values

不要不诚实

Connectivity,gorithm of Moore (BFS) we presented in Chapter 3 is an efficient method for determining the connected components of a graph. Now, in the present chapter, we mainly treat algorithmic questions concerning .-connectivity and strong connectivity for directed graphs. We develop a further strategy for sea

critic

Generator

Weighted Matchings,n particular to the problem of how to determine a matching of maximal weight in some network (.) (‘weighted matching’). In the bipartite case, this problem is equivalent to the ‘assignment problem’ (see Example 9.1.4), so that the methods introduced in Chapter 9 can be applied. However, we give a fu