(in-package #:metabang.graph)
-;;; ---------------------------------------------------------------------------
;;;
-;;; ---------------------------------------------------------------------------
(defstruct (vertex-datum (:conc-name node-) (:type list))
(color nil)
(depth most-positive-fixnum)
(parent nil))
-;;; ---------------------------------------------------------------------------
(defmethod initialize-vertex-data ((graph basic-graph))
(let ((vertex-data (make-container 'simple-associative-container)))
(make-vertex-datum :color :white))))
(values vertex-data)))
-;;; ---------------------------------------------------------------------------
;;; breadth-first-search by GWK
-;;; ---------------------------------------------------------------------------
(defmethod breadth-first-visitor ((graph basic-graph) (source t) fn)
(breadth-first-visitor graph (find-vertex graph source) fn))
-;;; ---------------------------------------------------------------------------
(defmethod breadth-first-visitor ((graph basic-graph) (source basic-vertex) fn)
;; initialize
vertex-data)))
-;;; ---------------------------------------------------------------------------
(defmethod breadth-first-search-graph ((graph basic-graph) (source t))
(breadth-first-search-graph graph (find-vertex graph source)))
-;;; ---------------------------------------------------------------------------
(defmethod breadth-first-search-graph ((graph basic-graph) (source basic-vertex))
;; initialize
vertex-data)))
-;;; ---------------------------------------------------------------------------
;;; single-source-shortest-paths - gwk
-;;; ---------------------------------------------------------------------------
#+NotYet
(defmethod single-source-shortest-paths ((graph basic-graph))
(setf (node-depth source-datum) 0))
))
-;;; ---------------------------------------------------------------------------
;;; connected-components - gwk
-;;; ---------------------------------------------------------------------------
(defmethod connected-components ((graph basic-graph))
(let ((union (make-container 'union-find-container)))
(iterate-elements union 'find-set)
union))
-;;; ---------------------------------------------------------------------------
(defmethod connected-component-count ((graph basic-graph))
;;?? Gary King 2005-11-28: Super ugh
-;;; ---------------------------------------------------------------------------
;;; minimum-spanning-tree based on kruskal's algorithm detailed in clrs2 -jjm
-;;; ---------------------------------------------------------------------------
(defmethod mst-find-set ((vertex basic-vertex))
#+ignore
(setf (previous-node vertex) (mst-find-set (previous-node vertex))))
(previous-node vertex))
-;;; ---------------------------------------------------------------------------
(defmethod mst-make-set ((vertex basic-vertex))
(setf (previous-node vertex) vertex
(rank vertex) 0))
-;;; ---------------------------------------------------------------------------
(defmethod mst-tree-union ((v1 basic-vertex) (v2 basic-vertex))
(mst-link (mst-find-set v1) (mst-find-set v2)))
-;;; ---------------------------------------------------------------------------
(defmethod mst-link ((v1 basic-vertex) (v2 basic-vertex))
(cond ((> (rank v1) (rank v2))
(when (= (rank v1) (rank v2))
(incf (rank v2))))))
-;;; ---------------------------------------------------------------------------
;;; jjm's implementation of mst depends on this
;;; todo - figure out some what to add and edge we create to a graph rather
;;; than always using add-edge-between-vertexes interface
-;;; ---------------------------------------------------------------------------
(defmethod add-edges-to-graph ((graph basic-graph) (edges list)
&key (if-duplicate-do :ignore))
:if-duplicate-do if-duplicate-do))))
graph)
-;;; ---------------------------------------------------------------------------
(defmethod edge-lessp-by-weight ((e1 basic-edge) (e2 basic-edge))
(< (weight e1) (weight e2)))
-;;; ---------------------------------------------------------------------------
;;; minumum spanning tree
-;;; ---------------------------------------------------------------------------
(defmethod minimum-spanning-tree ((graph basic-graph)
(values t result))
(t (values nil result)))))))
-;;; ---------------------------------------------------------------------------
#+ignore ;;; shoot
(defmethod minimum-spanning-tree ((vertex-list list)
(values t result))
(t (values nil result)))))))
-;;; ---------------------------------------------------------------------------
;;; uses mst to determine if the graph is connected
-;;; ---------------------------------------------------------------------------
(defmethod connected-graph-p ((graph basic-graph) &key
(edge-sorter 'edge-lessp-by-weight))
(minimum-spanning-tree graph :edge-sorter edge-sorter))
-;;; ---------------------------------------------------------------------------
#+test
(let ((g (make-container 'graph-container)))
:if-duplicate-do :force)
(minimum-spanning-tree g))
-;;; ---------------------------------------------------------------------------
;;; GWK's implementation of kruskal's - slightly faster, but it doesn't return
;;; a tree (still faster even if it does). Will decide later if which to use
;;; ignoring for now -jjm
-;;; ---------------------------------------------------------------------------
#+not-yet
(defmethod minimum-spanning-tree ((graph basic-graph) &key (weight 'weight))
(values a)))
-;;; ---------------------------------------------------------------------------
#+test
(loop for f in '(mst-kruskal minimum-spanning-tree-kruskal) do
(declare (ignore a b))
0)))))))
-;;; ---------------------------------------------------------------------------
;;; end minimum spanning tree
-;;; ---------------------------------------------------------------------------
-;;; ---------------------------------------------------------------------------
;;; depth-first-search - clrs2
;;; todo - figure out how to name this depth-first-search, which is already
;;; defined in search.lisp
-;;; ---------------------------------------------------------------------------
-;;; ---------------------------------------------------------------------------
;;; should probably make this special
-;;; ---------------------------------------------------------------------------
(defparameter *depth-first-search-timer* -1)
-;;; ---------------------------------------------------------------------------
;;; undirected edges are less than edges that are directed
-;;; ---------------------------------------------------------------------------
#+ignore ;;; incorrect, methinks - jjm
(defmethod edge-lessp-by-direction ((e1 basic-edge) (e2 basic-edge))
(defmethod edge-lessp-by-direction ((e1 basic-edge) (e2 basic-edge))
(and (undirected-edge-p e1) (directed-edge-p e2)))
-;;; ---------------------------------------------------------------------------
(defmethod out-edge-for-vertex-p ((edge basic-edge) (vertex basic-vertex))
(cond ((and (directed-edge-p edge)
t)
(t nil)))
-;;; ---------------------------------------------------------------------------
;;; depth-first-search
-;;; ---------------------------------------------------------------------------
(defmethod dfs ((graph basic-graph) (root t) fn &key
(out-edge-sorter #'edge-lessp-by-direction))
(dfs graph (find-vertex graph root) fn :out-edge-sorter out-edge-sorter))
-;;; ---------------------------------------------------------------------------
(defmethod dfs ((graph basic-graph) (root basic-vertex) fn &key
(out-edge-sorter #'edge-lessp-by-direction))
(sort (copy-list (vertexes graph)) #'< :key #'finish-time)
graph))
-;;; ---------------------------------------------------------------------------
(defmethod dfs-visit ((graph graph-container) (u basic-vertex)
fn sorter)
(setf (color u) :black
(finish-time u) *depth-first-search-timer*))
-;;; ---------------------------------------------------------------------------
;;; from clrs2
-;;; ---------------------------------------------------------------------------
#+test
(let ((g (make-container 'graph-container)))
(assert (equal '(:X :Y :V :U :Z :W)
(mapcar #'element (dfs g :u #'identity)))))
-;;; ---------------------------------------------------------------------------
(defmethod dfs-tree-edge-p ((edge graph-container-edge))
(eql (color edge) :white))
-;;; ---------------------------------------------------------------------------
(defmethod dfs-back-edge-p ((edge graph-container-edge))
(eql (color edge) :gray))
-;;; ---------------------------------------------------------------------------
;;; not correct - has to look at combination of discovery-time and finish-time
-;;; ---------------------------------------------------------------------------
(defmethod dfs-forward-edge-p ((edge graph-container-edge))
(warn "implementation is not correct.")
(< (discovery-time (source-vertex edge))
(discovery-time (target-vertex edge)))))
-;;; ---------------------------------------------------------------------------
;;; not correct - has to look at combination of discovery-time and finish-time
-;;; ---------------------------------------------------------------------------
(defmethod dfs-cross-edge-p ((edge graph-container-edge))
(warn "implementation is not correct.")
(> (discovery-time (source-vertex edge))
(discovery-time (target-vertex edge)))))
-;;; ---------------------------------------------------------------------------
(defmethod dfs-edge-type ((edge graph-container-edge))
(cond ((dfs-tree-edge-p edge)
:cross)
(t nil)))
-;;; ---------------------------------------------------------------------------
;;; end dfs
-;;; ---------------------------------------------------------------------------
-;;; ---------------------------------------------------------------------------
;;; mapping functions
-;;; ---------------------------------------------------------------------------
-;;; ---------------------------------------------------------------------------
;;; over vertexes
-;;; ---------------------------------------------------------------------------
(defmethod map-over-all-combinations-of-k-vertexes ((graph basic-graph) k fn)
(let* ((vertex-count (size graph))
(nth-element vertexes vertex-index))
vertex-indexes)))))))
-;;; ---------------------------------------------------------------------------
#+test
(let ((result nil)
(push graph-from-vertexes result)))))
result)
-;;; ---------------------------------------------------------------------------
;;; over edges
;;; todo: merge these two defs
-;;; ---------------------------------------------------------------------------
(defmethod map-over-all-combinations-of-k-edges ((graph basic-graph) k fn)
(let* ((edge-count (edge-count graph))
(nth-element edges edge-index))
edge-indexes)))))))
-;;; ---------------------------------------------------------------------------
(defmethod map-over-all-combinations-of-k-edges ((vertex basic-vertex) k fn)
(let* ((edge-count (edge-count vertex))
(funcall fn (mapcar (lambda (edge-index)
(nth-element edges edge-index))
edge-indexes)))))))
-;;; ---------------------------------------------------------------------------
#+test
(map-over-all-combinations-of-k-edges
projects / cl-graph.git / blobdiff