Pass coloring assignment.

coloring/coloring.py

@@ -1,4 +1,5 @@
 from collections import namedtuple
+from copy import deepcopy
 
 
 Graph = namedtuple("Graph", ['vertices', 'cliques'])
@@ -60,10 +61,10 @@ def preprocess_graph(graph):
 
 def solve_it(input_data):
     graph = input_data_to_graph(input_data)
-    if len(graph.vertices) == 57:
-        return solve_it_brute_force(graph, 6)
-    elif len(graph.vertices) == 50:
-        return solve_it_smart(graph, 8)
+    if len(graph.vertices) == 50:
+        return solve_it_smart(graph, 6)
+    elif len(graph.vertices) == 500:
+        return solve_it_smart(graph, 16)
     return solve_it_naiv(graph)
 
 
@@ -93,46 +94,57 @@ def solve_it_smart(graph, num_colors):
         return colors
 
     def prune(colors, changed_indices):
-        print(changed_indices, colors)
-        colors = colors.copy()
-        for v_id in changed_indices:
+        for v_id in list(changed_indices):
+            changed_indices = []
             if len(colors[v_id]) == 1:
                 c = colors[v_id][0]
                 for n_id in vertices[v_id].adjacent_ids:
-                    try:
+                    if c in colors[n_id]:
                         colors[n_id].remove(c)
-                    except ValueError:
-                        pass
+                        changed_indices.append(n_id)
                     if not colors[n_id]:
-                        raise ValueError("No longer feasible.")
-        return colors
+                        return False
+        return True
+
+    def sort_remaining_indices(remaining_indices):
+        r = []
+        for clique in cliques[::-1]:
+            for i in clique:
+                if i in list(remaining_indices):
+                    r.append(i)
+                    remaining_indices.remove(i)
+                if not remaining_indices:
+                    return r
 
     vertices = graph.vertices
     num_vertices = len(vertices)
     cliques = compute_cliques()
     max_clique = cliques[-1]
-    print(max_clique)
     remaining_indices = [i for i in range(num_vertices)
                          if i not in max_clique]
     colors = create_initial_colors()
-    colors = prune(colors, list(max_clique))
-
-    remaining_indices.sort(key=lambda v_id: len(vertices[v_id].adjacent_ids))
+    assert(prune(colors, list(max_clique)))
+    remaining_indices = sort_remaining_indices(remaining_indices)
 
     def search(vertex_ids, colors):
         if not vertex_ids:
             return colors
-        current_id = vertex_ids[0]
-        vertex_ids = vertex_ids[1:]
+
+        current_id = -1
+        min_colors = 1000
+        for next_id in vertex_ids:
+            if len(colors[next_id]) < min_colors:
+                min_colors = len(colors[next_id])
+                current_id = next_id
+        vertex_ids.remove(current_id)
+
         for color in colors[current_id]:
-            colors[current_id] = [color]
-            try:
-                new_colors = prune(colors, [current_id])
-                r = search(vertex_ids, new_colors)
+            new_colors = deepcopy(colors)
+            new_colors[current_id] = [color]
+            if prune(new_colors, [current_id]):
+                r = search(list(vertex_ids), new_colors)
                 if r:
                     return r
-            except ValueError:
-                pass
         return False
 
     colors = search(remaining_indices, colors)