040000 tree 449ec8ebb915c6fa56635b864ffd9689e278c0ce	alg.merge
040000 tree 3618d93af552ad2391a3d8f4efc2bc77e777714f	alg.modifying.operations
040000 tree fdf650d656cb1fc3a7e3f47ed30e21046da9dca6	alg.nonmodifying
040000 tree 0e5107c4f5d39799a5c6b82cb42c46fccbbe4381	alg.sorting