1. An apparatus, comprising: a processor and a memory communicatively connected to the processor, the processor configured to: receive a representation of pairwise cost information for a set of nodes; determine a clustering of the nodes into a set of clusters; and sparsify the representation of pairwise cost information for the set of nodes, based on the clustering of the nodes into the set of clusters, to form a sparsified representation of the pairwise cost information for the set of nodes; wherein, to sparsify the representation of the pairwise cost information for the set of nodes, the processor is configured to: determine, for at least one of the clusters based on the pairwise cost information for the set of nodes, a respective intra-cluster cost for the respective cluster that is indicative of an average minimum cost between pairs of nodes of the respective cluster; and determine, for at least one pair of clusters based on the pairwise cost information for the set of nodes, a respective inter-cluster cost for the respective pair of clusters that is indicative of an average minimum cost between pairs of nodes included in respective clusters in the respective pair of clusters; wherein the sparsified representation of the pairwise cost information for the set of nodes comprises a matrix of cells, wherein ones of the cells associated with respective ones of the clusters include the respective intra-cluster costs for the respective ones of the clusters, wherein ones of the cells associated with respective pairs of the clusters include the respective inter-cluster costs for the respective pairs of the clusters.