93 lines
2.5 KiB
Factor
93 lines
2.5 KiB
Factor
|
! Copyright (C) 2008 William Schlieper <schlieper@unc.edu>
|
||
|
|
! See http://factorcode.org/license.txt for BSD license.
|
||
|
|
|
||
|
|
USING: kernel combinators fry continuations sequences arrays vectors assocs hashtables heaps namespaces ;
|
||
|
|
|
||
|
|
IN: graph-theory
|
||
|
|
|
||
|
|
MIXIN: graph
|
||
|
|
SYMBOL: visited?
|
||
|
|
ERROR: end-search ;
|
||
|
|
|
||
|
|
GENERIC: vertices ( graph -- seq ) flushable
|
||
|
|
|
||
|
|
GENERIC: num-vertices ( graph -- n ) flushable
|
||
|
|
|
||
|
|
GENERIC: num-edges ( graph -- n ) flushable
|
||
|
|
|
||
|
|
GENERIC: adjlist ( from graph -- seq ) flushable
|
||
|
|
|
||
|
|
GENERIC: adj? ( from to graph -- ? ) flushable
|
||
|
|
|
||
|
|
GENERIC: add-blank-vertex ( index graph -- )
|
||
|
|
|
||
|
|
GENERIC: delete-blank-vertex ( index graph -- )
|
||
|
|
|
||
|
|
GENERIC: add-edge* ( from to graph -- )
|
||
|
|
|
||
|
|
GENERIC: add-edge ( u v graph -- )
|
||
|
|
|
||
|
|
GENERIC: delete-edge* ( from to graph -- )
|
||
|
|
|
||
|
|
GENERIC: delete-edge ( u v graph -- )
|
||
|
|
|
||
|
|
M: graph num-vertices
|
||
|
|
vertices length ;
|
||
|
|
|
||
|
|
M: graph num-edges
|
||
|
|
[ vertices ] [ '[ , adjlist length ] map sum ] bi ;
|
||
|
|
|
||
|
|
M: graph adjlist
|
||
|
|
[ vertices ] [ swapd '[ , swap , adj? ] filter ] bi ;
|
||
|
|
|
||
|
|
M: graph adj?
|
||
|
|
swapd adjlist index >boolean ;
|
||
|
|
|
||
|
|
M: graph add-edge
|
||
|
|
[ add-edge* ] [ swapd add-edge* ] 3bi ;
|
||
|
|
|
||
|
|
M: graph delete-edge
|
||
|
|
[ delete-edge* ] [ swapd delete-edge* ] 3bi ;
|
||
|
|
|
||
|
|
: add-blank-vertices ( seq graph -- )
|
||
|
|
'[ , add-blank-vertex ] each ;
|
||
|
|
|
||
|
|
: delete-vertex ( index graph -- )
|
||
|
|
[ adjlist ]
|
||
|
|
[ '[ , , 3dup adj? [ delete-edge* ] [ 3drop ] if ] each ]
|
||
|
|
[ delete-blank-vertex ] 2tri ;
|
||
|
|
|
||
|
|
<PRIVATE
|
||
|
|
|
||
|
|
: search-wrap ( quot graph -- ? )
|
||
|
|
[ [ graph set ] [ vertices [ f 2array ] map >hashtable visited? set ] bi
|
||
|
|
[ t ] compose [ dup end-search? [ drop f ] [ rethrow ] if ] recover ] with-scope ; inline
|
||
|
|
|
||
|
|
: (depth-first) ( v pre post -- )
|
||
|
|
{ [ 2drop visited? get t -rot set-at ]
|
||
|
|
[ drop call ]
|
||
|
|
[ [ graph get adjlist ] 2dip
|
||
|
|
'[ dup visited? get at [ drop ] [ , , (depth-first) ] if ] each ]
|
||
|
|
[ nip call ] } 3cleave ; inline
|
||
|
|
|
||
|
|
PRIVATE>
|
||
|
|
|
||
|
|
: depth-first ( v graph pre post -- ?list ? )
|
||
|
|
'[ , , (depth-first) visited? get ] swap search-wrap ; inline
|
||
|
|
|
||
|
|
: full-depth-first ( graph pre post tail -- ? )
|
||
|
|
'[ [ visited? get [ nip not ] assoc-find ]
|
||
|
|
[ drop , , (depth-first) @ ]
|
||
|
|
[ 2drop ] while ] swap search-wrap ; inline
|
||
|
|
|
||
|
|
: dag? ( graph -- ? )
|
||
|
|
V{ } clone swap [ 2dup swap push dupd
|
||
|
|
'[ , swap graph get adj? not ] all?
|
||
|
|
[ end-search ] unless ]
|
||
|
|
[ drop dup pop* ] [ ] full-depth-first nip ;
|
||
|
|
|
||
|
|
: topological-sort ( graph -- seq/f )
|
||
|
|
dup dag?
|
||
|
|
[ V{ } swap [ drop ] [ prefix ] [ ] full-depth-first drop ]
|
||
|
|
[ drop f ] if ;
|