diff options
Diffstat (limited to 'algos.c')
-rw-r--r-- | algos.c | 73 |
1 files changed, 65 insertions, 8 deletions
@@ -82,7 +82,6 @@ int color_subgraph(const graph g, set s, int dump_colors) { set_remove_ip(vertices[i], s); i++; } - assert(i == n); // Calculate neighbour count for all nodes for (i = 0; i < n; i++) nneigh[i] = 0; @@ -183,10 +182,7 @@ void max_clique_b(const graph g, set k, set c, set a, set *mc) { // argument peuvent être modifiés à la guise de l'algorithme // Il est donc de la responsabilité de l'appellant de vérifier qu'à // chaque appel les sets sont utilisables et cohérents -int blabla = 0; -void max_clique_c(const graph g, set k, set c, set a, set *mc, int prev_size) { - blabla++; - //if (blabla % 100 == 0) printf("%d\n", blabla); +void max_clique_c(const graph g, set k, set c, set a, set *mc) { // If we have no chance of improving our max clique, exit if (set_size(k) + set_size(c) <= set_size(*mc)) return; @@ -200,7 +196,69 @@ void max_clique_c(const graph g, set k, set c, set a, set *mc, int prev_size) { // If we have no possibility to explore, return if (is_set_empty(c)) return; - if (set_size(c) <= prev_size / 2 && set_size(c) >= g->N / 20) { + // Find u that maximises |C inter Gamma(u)| + set c_it = copy_set(c); + int u = elt_of_set(c_it), n = 0; + set_remove_ip(u, c_it); + + { set temp = set_inter(c, graph_neighbours(g, u)); + n = set_size(temp); + delete_set(temp); + } + + // Explore possibilites + int heur = u; + while (!is_set_empty(c_it)) { + int uprime = elt_of_set_heur(c_it, heur); + set_remove_ip(uprime, c_it); + heur = uprime; + + set temp = set_inter(c, graph_neighbours(g, uprime)); + if (set_size(temp) > n) { + n = set_size(temp); + u = uprime; + } + delete_set(temp); + } + delete_set(c_it); + + + set t = set_diff(a, graph_neighbours(g, u)); + heur = u; + while (!is_set_empty(t)) { + int x = elt_of_set_heur(t, heur); + heur = x; + + set k2 = set_add(x, k); + set c2 = set_inter(c, graph_neighbours(g, x)); + set a2 = set_inter(a, graph_neighbours(g, x)); + max_clique_c(g, k2, c2, a2, mc); + delete_set(a2); + delete_set(c2); + delete_set(k2); + + set_remove_ip(x, a); + delete_set(t); + t = set_diff(a, graph_neighbours(g, u)); + } + delete_set(t); +} + +void max_clique_c_color(const graph g, set k, set c, set a, set *mc, int prev_size) { + // If we have no chance of improving our max clique, exit + if (set_size(k) + set_size(c) <= set_size(*mc)) return; + + // If we have improved our clique, great + if (set_size(k) > set_size(*mc)) { + delete_set(*mc); + *mc = copy_set(k); + printf("Found new max clique: "); dump_set(*mc); fflush(stdout); + } + + // If we have no possibility to explore, return + if (is_set_empty(c)) return; + + if (set_size(c) <= prev_size / 2 && (set_size(c) >= 20 || set_size(c) >= g->N / 24)) { prev_size = set_size(c); // Color graph : we may have no possibility set c_copy = copy_set(c); @@ -246,8 +304,7 @@ void max_clique_c(const graph g, set k, set c, set a, set *mc, int prev_size) { set k2 = set_add(x, k); set c2 = set_inter(c, graph_neighbours(g, x)); set a2 = set_inter(a, graph_neighbours(g, x)); - assert(!set_mem(x, c2)); - max_clique_c(g, k2, c2, a2, mc, prev_size); + max_clique_c_color(g, k2, c2, a2, mc, prev_size); delete_set(a2); delete_set(c2); delete_set(k2); |