/usr/include/sparsehash/ is in libsparsehash-dev 2.0.2-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/sparsehash/dense_hash_map
/usr/include/sparsehash/dense_hash_set
/usr/include/sparsehash/internal/
/usr/include/sparsehash/internal/densehashtable.h
/usr/include/sparsehash/internal/hashtable-common.h
/usr/include/sparsehash/internal/libc_allocator_with_realloc.h
/usr/include/sparsehash/internal/sparseconfig.h
/usr/include/sparsehash/internal/sparsehashtable.h
/usr/include/sparsehash/sparse_hash_map
/usr/include/sparsehash/sparse_hash_set
/usr/include/sparsehash/sparsetable
/usr/include/sparsehash/template_util.h
/usr/include/sparsehash/type_traits.h