/usr/include/mlpack/methods/kmeans/ is in libmlpack-dev 2.1.1-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/mlpack/methods/kmeans/allow_empty_clusters.hpp
/usr/include/mlpack/methods/kmeans/dual_tree_kmeans.hpp
/usr/include/mlpack/methods/kmeans/dual_tree_kmeans_impl.hpp
/usr/include/mlpack/methods/kmeans/dual_tree_kmeans_rules.hpp
/usr/include/mlpack/methods/kmeans/dual_tree_kmeans_rules_impl.hpp
/usr/include/mlpack/methods/kmeans/dual_tree_kmeans_statistic.hpp
/usr/include/mlpack/methods/kmeans/elkan_kmeans.hpp
/usr/include/mlpack/methods/kmeans/elkan_kmeans_impl.hpp
/usr/include/mlpack/methods/kmeans/hamerly_kmeans.hpp
/usr/include/mlpack/methods/kmeans/hamerly_kmeans_impl.hpp
/usr/include/mlpack/methods/kmeans/kill_empty_clusters.hpp
/usr/include/mlpack/methods/kmeans/kmeans.hpp
/usr/include/mlpack/methods/kmeans/kmeans_impl.hpp
/usr/include/mlpack/methods/kmeans/max_variance_new_cluster.hpp
/usr/include/mlpack/methods/kmeans/max_variance_new_cluster_impl.hpp
/usr/include/mlpack/methods/kmeans/naive_kmeans.hpp
/usr/include/mlpack/methods/kmeans/naive_kmeans_impl.hpp
/usr/include/mlpack/methods/kmeans/pelleg_moore_kmeans.hpp
/usr/include/mlpack/methods/kmeans/pelleg_moore_kmeans_impl.hpp
/usr/include/mlpack/methods/kmeans/pelleg_moore_kmeans_rules.hpp
/usr/include/mlpack/methods/kmeans/pelleg_moore_kmeans_rules_impl.hpp
/usr/include/mlpack/methods/kmeans/pelleg_moore_kmeans_statistic.hpp
/usr/include/mlpack/methods/kmeans/random_partition.hpp
/usr/include/mlpack/methods/kmeans/refined_start.hpp
/usr/include/mlpack/methods/kmeans/refined_start_impl.hpp
/usr/include/mlpack/methods/kmeans/sample_initialization.hpp