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Diffstat (limited to 'src/lib/eina_graph_dfs.c')
| -rw-r--r-- | src/lib/eina_graph_dfs.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/src/lib/eina_graph_dfs.c b/src/lib/eina_graph_dfs.c new file mode 100644 index 0000000..3fa08a6 --- /dev/null +++ b/src/lib/eina_graph_dfs.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_dfs.h> +#include "eina_graph_private.h" + +static void +_eina_graph_dfs_swalk(_Eina_Graph *_g, _Eina_Graph_DFS *_dfs, unsigned int v) +{ + Eina_List *stack = NULL; + Eina_Graph_Adjacents *adjs; + unsigned int p, w, n, i; + + p = v; + stack = eina_list_prepend(stack, (void *) v); + + while (eina_list_count(stack) > 0) + { + w = (unsigned int) eina_list_data_get(stack); + stack = eina_list_remove(stack, (void *) w); + + if(_dfs->marked[w]) continue; + _dfs->marked[w] = EINA_TRUE; + _dfs->edge_to[w] = p; + p = w; + + adjs = &_g->adjs[w]; + n = adjs->count; + for (i = 0; i < n; i++) + { + w = adjs->data[i]; + if (!_dfs->marked[w]) + { + stack = eina_list_prepend(stack, (void *) w); + } + } + } +} + +static void +_eina_graph_dfs_rwalk(_Eina_Graph *_g, _Eina_Graph_DFS *_dfs, unsigned int v) +{ + Eina_Graph_Adjacents *adjs; + unsigned int i, n, w; + + _dfs->marked[v] = EINA_TRUE; + + adjs = &_g->adjs[v]; + n = adjs->count; + for (i = 0; i < n; i++) + { + w = adjs->data[i]; + if (!_dfs->marked[w]) + { + _eina_graph_dfs_rwalk(_g, _dfs, w); + _dfs->edge_to[w] = v; + } + } +} + +EAPI Eina_Graph_DFS * +eina_graph_dfs_new(Eina_Graph *g, unsigned int s, Eina_Bool r) +{ + _Eina_Graph_DFS *_dfs; + _Eina_Graph * _g = (_Eina_Graph *) g; + + _dfs = calloc(1, sizeof(_Eina_Graph_DFS)); + if (!_dfs) + goto error_dfs; + + _dfs->marked = calloc(_g->vertices, sizeof(Eina_Bool)); + if (!_dfs->marked) + goto error_marked; + + _dfs->edge_to = calloc(_g->vertices, sizeof(unsigned int)); + if (!_dfs->edge_to) + goto error_edge_to; + + _dfs->s = s; + _dfs->vertices = _g->vertices; + + if (r) + _eina_graph_dfs_rwalk(_g, _dfs, s); + else + _eina_graph_dfs_swalk(_g, _dfs, s); + + return (Eina_Graph_DFS *) _dfs; + +error_edge_to: + free(_dfs->marked); +error_marked: + free(_dfs); +error_dfs: + ERR("calloc failed : %s", strerror(errno)); + return NULL; +} + +EAPI void +eina_graph_dfs_free(Eina_Graph_DFS *dfs) +{ + _Eina_Graph_DFS *_dfs = (_Eina_Graph_DFS *) dfs; + + free(_dfs->marked); + free(_dfs->edge_to); + free(_dfs); +} + +EAPI unsigned int +eina_graph_dfs_source(Eina_Graph_DFS *dfs) +{ + _Eina_Graph_DFS *_dfs = (_Eina_Graph_DFS *) dfs; + + return _dfs->s; +} + +EAPI Eina_Bool +eina_graph_dfs_has_path_to(Eina_Graph_DFS *dfs, unsigned int v) +{ + _Eina_Graph_DFS *_dfs = (_Eina_Graph_DFS *) dfs; + + if (v >= _dfs->vertices) + { + ERR("%u is out of [0;%u[", v, _dfs->vertices); + return EINA_FALSE; + } + + return _dfs->marked[v]; +} + +EAPI Eina_List * +eina_graph_dfs_path_to(Eina_Graph_DFS *dfs, unsigned int v) +{ + unsigned int w = v; + Eina_List *path = NULL; + _Eina_Graph_DFS *_dfs = (_Eina_Graph_DFS *) dfs; + + if (v >= _dfs->vertices) + { + ERR("%u is out of [0;%u[", v, _dfs->vertices); + return NULL; + } + + if (!_dfs->marked[v]) + return NULL; + + while (w != _dfs->s) + { + path = eina_list_prepend(path, (void *) w); + w = _dfs->edge_to[w]; + } + path = eina_list_prepend(path, (void *) _dfs->s); + + return path; +} + |