slightly ok pruning based on max score of other branches of DFS and

modifying depth of branch by pieces taken

checkers.rb

@@ -234,69 +234,93 @@ class Board
 		return boards
 	end
 
-	def score(team)
-		score = 0
-		score += @stats[team]['count']
-		score += 12 - @stats[opposite_team(team)]['count']
-		if @stats[opposite_team(team)]['count'] == 0
-			score += 12
-		elsif @stats[team]['count'] == 0
-			score -= 12
-		end
-		return score	
+	def score()
+		scores = {}
+		[TEAM_1, TEAM_2].each {|team|
+			score = 0
+			score += @stats[team]['count']
+			score += 12 - @stats[opposite_team(team)]['count']
+			if @stats[opposite_team(team)]['count'] == 0
+				score += 12
+			elsif @stats[team]['count'] == 0
+				score -= 12
+			end
+			scores[team] = score
+		}
+		return scores	
 	end
 
 	def search(team)
-		search_do(team, 0, 10, 100.0, 0.0, "R", {TEAM_1 => -100, TEAM_2 =>  -100})
+		search_do(team, team, 0, 6, 100.0, 0.0, @stats.dup, [])
 	end
 
+	# the owner of the search: affects pruning bonuses
         # team - current player this turn
         # current depth - counting up to max_depth
         # max_depth - when we should stop our search
         # my_percent - the percent range this work covers
         # done_percent - the percent of work already done
-        # maxs - 
-	def search_do(team, current_depth, max_depth, my_percent, done_percent, maxs)
-		#puts location
-		if depth == 0
-			return score(team)
+	# stats - stats from 2 turns ago, ie before most recent opponent turn
+	# maxs - depth indexed array of max scores
+	def search_do(owner, team, current_depth, max_depth, my_percent, done_percent, stats, maxs)
+		#puts current_depth.to_s + '/' + max_depth.to_s + ' ' + done_percent.to_s + "%"
+
+		if current_depth < maxs.length and score()[team] < maxs[current_depth][team]
+			return score()
 		end
+		if current_depth >= maxs.length or score()[team] > maxs[current_depth][team]
+			maxs[current_depth] = score()
+		end
+		
+		if current_depth >= max_depth
+			return score()
+		end
+
 		if @stats[TEAM_1]['count'] == 0
 			puts "TEAM_2 WON!"
-			return score(team) 
+			return score()
 		elsif @stats[TEAM_2]['count'] == 0
 			puts "TEAM_1 WON!"
-			return score(team) 
+			puts to_s
+			return score()
 		else
 			moves = gen_next_move_boards(team)
 			if moves == []
 				puts "NO MOVES AVAILABLE?"
-				return score(team)
+				return score()
 			else
 				jumps = moves.find_all { |item| item['move'][0].is_a?(Array)}
 				if jumps.length > 0
 					moves = jumps
 				end
 				done = 0.0
-				item_percent = percent/moves.length
-
+				item_percent = my_percent/moves.length
+				max = nil
 				for i in 0..moves.length-1 do
-					#moves.each { |move|
+					depth_mod = 0
 					move = moves[i]['board']
-					#puts "SEARCH"
-        				sub_score = move.search_do(opposite_team(team), depth -1, item_percent, last_percent+done, location + "." +i.to_s, maxs.dup )
+					# modify depth on piece loss
+        				if  stats[team]['count'] > move.stats[team]['count']
+						# search less is search owner lost peices
+						if owner == team
+							depth_mod = -4
+						else
+							depth_mod = 4
+						end
+					end
+					sub_score = move.search_do(owner, opposite_team(team), current_depth + 1, max_depth + depth_mod, item_percent, done_percent+done,  @stats.dup, maxs)
        					done += item_percent
 					if done >= 0.01
-          					last_percent += done;
-						puts "%.5f" % last_percent + "% depth: " + depth.to_s + " max: " + maxs.to_s
+          					done_percent += done;
+						puts "%.2f" % done_percent + "% depth: " + current_depth.to_s + "/" + max_depth.to_s + " max: " + maxs.to_s
 						done = 0.0
         				end
 					#puts "Score: " + sub_score.to_s
-					if sub_score > maxs[team]
-						maxs[team] = sub_score
+					if max == nil or sub_score[team] > max[team]
+						max = sub_score
 					end
 				end
-				return maxs[team]
+				return max
 			end
 		 end
 	end