Constrained via minimization

It is shown that the general two-layer constrained via minimization problem and the three-layer constrained via minimization problem for HVH topologies are NP-hard. A backtracking algorithm and a heuristic algorithm for the three-layer HVH constrained via minimization problem are proposed. The backtracking algorithm can also be used for three-layer non-HVH problems. Experimental results indicate that the heuristic generally outperforms that of K. Chang et al. (unpublished).<
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