From 9046058f42d73db174acd6d6cda6fecc34b63c78 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=94=D0=BE=D0=B1=D1=80=D1=8B=D0=B8=CC=86=20=D0=AD=D1=8D?=
 =?UTF-8?q?=D1=85?= <bukharaev@gmail.com>
Date: Fri, 14 Apr 2017 18:02:04 +0300
Subject: [PATCH] [routing] Bidirectional Astar optimization

---
 routing/base/astar_algorithm.hpp | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/routing/base/astar_algorithm.hpp b/routing/base/astar_algorithm.hpp
index a17738210f..b1ba850a9e 100644
--- a/routing/base/astar_algorithm.hpp
+++ b/routing/base/astar_algorithm.hpp
@@ -110,6 +110,8 @@ private:
     BidirectionalStepContext(bool forward, TVertexType const & startVertex,
                              TVertexType const & finalVertex, TGraphType & graph)
         : forward(forward), startVertex(startVertex), finalVertex(finalVertex), graph(graph)
+        , m_piRT(graph.HeuristicCostEstimate(finalVertex, startVertex))
+        , m_piFS(graph.HeuristicCostEstimate(startVertex, finalVertex))
     {
       bestVertex = forward ? startVertex : finalVertex;
       pS = ConsistentHeuristic(bestVertex);
@@ -128,19 +130,17 @@ private:
     {
       double const piF = graph.HeuristicCostEstimate(v, finalVertex);
       double const piR = graph.HeuristicCostEstimate(v, startVertex);
-      double const piRT = graph.HeuristicCostEstimate(finalVertex, startVertex);
-      double const piFS = graph.HeuristicCostEstimate(startVertex, finalVertex);
       if (forward)
       {
         /// @todo careful: with this "return" here and below in the Backward case
         /// the heuristic becomes inconsistent but still seems to work.
         /// return HeuristicCostEstimate(v, finalVertex);
-        return 0.5 * (piF - piR + piRT);
+        return 0.5 * (piF - piR + m_piRT);
       }
       else
       {
         // return HeuristicCostEstimate(v, startVertex);
-        return 0.5 * (piR - piF + piFS);
+        return 0.5 * (piR - piF + m_piFS);
       }
     }
 
@@ -156,6 +156,8 @@ private:
     TVertexType const & startVertex;
     TVertexType const & finalVertex;
     TGraph & graph;
+    double const m_piRT;
+    double const m_piFS;
 
     priority_queue<State, vector<State>, greater<State>> queue;
     map<TVertexType, double> bestDistance;