diff options
Diffstat (limited to 'src/lib/eina_graph_bfs.c')
-rw-r--r-- | src/lib/eina_graph_bfs.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/src/lib/eina_graph_bfs.c b/src/lib/eina_graph_bfs.c new file mode 100644 index 0000000..36cbdbc --- /dev/null +++ b/src/lib/eina_graph_bfs.c @@ -0,0 +1,184 @@ +/* EINA_GRAPH - EFL graph processing library + * Copyright (C) 2013 Jérémy Zurcher + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies of the Software and its Copyright notices. In addition publicly + * documented acknowledgment must be given that this software has been used if no + * source code of this software is made available publicly. This includes + * acknowledgments in either Copyright notices, Manuals, Publicity and Marketing + * documents or any documentation provided with any product containing this + * software. This License does not apply to any software that links to the + * libraries provided by this software (statically or dynamically), but only to + * the software provided. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER + * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif /* HAVE_CONFIG_H */ + +#include <eina_graph_bfs.h> +#include "eina_graph_private.h" + +static void +_eina_graph_bfs_fwalk(_Eina_Graph *_g, _Eina_Graph_BFS *_bfs, unsigned int v) +{ + Eina_List *fifo = NULL; + Eina_Graph_Adjacents *adjs; + unsigned int p, w, n, i, d; + + d = 0; + _bfs->marked[v] = EINA_TRUE; + _bfs->edge_to[v] = v; + _bfs->dist_to[v] = d; + fifo = eina_list_append(fifo, CAST_V(v)); + + while (eina_list_count(fifo) > 0) + { + w = CAST_D(eina_list_data_get(fifo)); + fifo = eina_list_remove(fifo, CAST_V(w)); + + p = w; + d++; + + adjs = &_g->adjs[w]; + n = adjs->count; + for (i = 0; i < n; i++) + { + w = adjs->data[i]; + if (!_bfs->marked[w]) + { + _bfs->marked[w] = EINA_TRUE; + _bfs->edge_to[w] = p; + _bfs->dist_to[w] = d; + fifo = eina_list_append(fifo, CAST_V(w)); + } + } + } +} + +EAPI Eina_Graph_BFS * +eina_graph_bfs_new(Eina_Graph *g, unsigned int s) +{ + _Eina_Graph_BFS *_bfs; + _Eina_Graph * _g = (_Eina_Graph *) g; + + _bfs = calloc(1, sizeof(_Eina_Graph_BFS)); + if (!_bfs) + goto error_bfs; + + _bfs->marked = calloc(_g->vertices, sizeof(Eina_Bool)); + if (!_bfs->marked) + goto error_marked; + + _bfs->edge_to = calloc(_g->vertices, sizeof(unsigned int)); + if (!_bfs->edge_to) + goto error_edge_to; + + _bfs->dist_to = calloc(_g->vertices, sizeof(unsigned int)); + if (!_bfs->dist_to) + goto error_dist_to; + + _bfs->s = s; + _bfs->vertices = _g->vertices; + + _eina_graph_bfs_fwalk(_g, _bfs, s); + + return (Eina_Graph_BFS *) _bfs; + +error_dist_to: + free(_bfs->edge_to); +error_edge_to: + free(_bfs->marked); +error_marked: + free(_bfs); +error_bfs: + ERR("calloc failed : %s", strerror(errno)); + return NULL; +} + +EAPI void +eina_graph_bfs_free(Eina_Graph_BFS *bfs) +{ + _Eina_Graph_BFS *_bfs = (_Eina_Graph_BFS *) bfs; + + free(_bfs->marked); + free(_bfs->edge_to); + free(_bfs->dist_to); + free(_bfs); +} + +EAPI unsigned int +eina_graph_bfs_source(Eina_Graph_BFS *bfs) +{ + _Eina_Graph_BFS *_bfs = (_Eina_Graph_BFS *) bfs; + + return _bfs->s; +} + +EAPI Eina_Bool +eina_graph_bfs_has_path_to(Eina_Graph_BFS *bfs, unsigned int v) +{ + _Eina_Graph_BFS *_bfs = (_Eina_Graph_BFS *) bfs; + + if (v >= _bfs->vertices) + { + ERR("%u is out of [0;%u[", v, _bfs->vertices); + return EINA_FALSE; + } + + return _bfs->marked[v]; +} + +EAPI Eina_List * +eina_graph_bfs_path_to(Eina_Graph_BFS *bfs, unsigned int v) +{ + unsigned int w = v; + Eina_List *path = NULL; + _Eina_Graph_BFS *_bfs = (_Eina_Graph_BFS *) bfs; + + if (v >= _bfs->vertices) + { + ERR("%u is out of [0;%u[", v, _bfs->vertices); + return NULL; + } + + if (!_bfs->marked[v]) + return NULL; + + while (w != _bfs->s) + { + path = eina_list_prepend(path, CAST_V(w)); + w = _bfs->edge_to[w]; + } + path = eina_list_prepend(path, CAST_V(_bfs->s)); + + return path; +} + +EAPI unsigned int +eina_graph_bfs_dist_to(Eina_Graph_BFS *bfs, unsigned int v) +{ + _Eina_Graph_BFS *_bfs = (_Eina_Graph_BFS *) bfs; + + if (v >= _bfs->vertices) + { + ERR("%u is out of [0;%u[", v, _bfs->vertices); + return UINT_MAX; + } + + return _bfs->dist_to[v]; +} |