diff --git a/include/BusFCFSStrategy.h b/include/BusFCFSStrategy.h
index cc1070e..ab01db3 100644
--- a/include/BusFCFSStrategy.h
+++ b/include/BusFCFSStrategy.h
@@ -8,11 +8,11 @@
 
 class BusFCFSStrategy : public BusStrategyBase
 {
-    int GetBusDirection();
+    int GetBusDirection() override;
 
-    bus_query_t *GetTargetQuery();
+    bus_query_t *GetTargetQuery() override;
 
-    bus_query_t *HandleBTWQuery();
+    bus_query_t *HandleBTWQuery() override;
 };
 
 
diff --git a/include/BusSCANStrategy.h b/include/BusSCANStrategy.h
index 7a48cba..3ef96c3 100644
--- a/include/BusSCANStrategy.h
+++ b/include/BusSCANStrategy.h
@@ -9,11 +9,11 @@
 
 class BusSCANStrategy : public BusStrategyBase
 {
-    int GetBusDirection();
+    int GetBusDirection() override;
 
-    bus_query_t *GetTargetQuery();
+    bus_query_t *GetTargetQuery() override;
 
-    bus_query_t *HandleBTWQuery();
+    bus_query_t *HandleBTWQuery() override;
 
 };
 
diff --git a/include/BusSSTFStrategy.h b/include/BusSSTFStrategy.h
index 35d8c41..0aed03f 100644
--- a/include/BusSSTFStrategy.h
+++ b/include/BusSSTFStrategy.h
@@ -8,11 +8,11 @@
 
 class BusSSTFStrategy : public BusStrategyBase
 {
-    int GetBusDirection();
+    int GetBusDirection() override;
 
-    bus_query_t *GetTargetQuery();
+    bus_query_t *GetTargetQuery() override;
 
-    bus_query_t *HandleBTWQuery();
+    bus_query_t *HandleBTWQuery() override;
 };
 
 
diff --git a/include/BusStrategyBase.h b/include/BusStrategyBase.h
index faf5eb1..97d3477 100644
--- a/include/BusStrategyBase.h
+++ b/include/BusStrategyBase.h
@@ -44,7 +44,7 @@ public:
 
     BusStrategyBase();
 
-    virtual ~BusStrategyBase();
+    ~BusStrategyBase() override;
 
     /**
      * 获得当前公交车应该前进的方向
diff --git a/include/PosPair.h b/include/PosPair.h
index 4705d77..c445811 100644
--- a/include/PosPair.h
+++ b/include/PosPair.h
@@ -47,7 +47,7 @@ public:
      * @param stop_number 站点的数量
      * @return 站点之间的距离
      */
-    int GetStopSpaceLength(int stop_number) const;
+    static int GetStopSpaceLength(int stop_number) ;
 
     /**
      * 加上一定的距离
diff --git a/src/PosPair.cpp b/src/PosPair.cpp
index 615867b..9293eb3 100644
--- a/src/PosPair.cpp
+++ b/src/PosPair.cpp
@@ -10,7 +10,7 @@ PosPair::PosPair()
     pos_y = stop_begin_y;
 }
 
-int PosPair::GetStopSpaceLength(int stop_number) const
+int PosPair::GetStopSpaceLength(int stop_number)
 {
     return 2 * (stop_rail_width + stop_rail_height) / stop_number;
 }
diff --git a/src/StrategyFactory.cpp b/src/StrategyFactory.cpp
index 831e259..de75c8d 100644
--- a/src/StrategyFactory.cpp
+++ b/src/StrategyFactory.cpp
@@ -131,15 +131,13 @@ BusStrategyBase *StrategyFactory::GetStrategy(const QString& file_name)
             break;
         case BUS_SCAN:
             controller = new BusSCANStrategy;
+            break;
         default:
             controller = nullptr;
             break;
     }
 
-    if(controller != nullptr)
-    {
-        controller->rails_model->CreateRails(distance, total_station);
-        controller->strategy = chosen_strategy;
-    }
+    controller->rails_model->CreateRails(distance, total_station);
+    controller->strategy = chosen_strategy;
     return controller;
 }
diff --git a/src/busModel.cpp b/src/busModel.cpp
index bcb8e6d..1c2ecc4 100644
--- a/src/busModel.cpp
+++ b/src/busModel.cpp
@@ -13,9 +13,7 @@ BusModel::BusModel()
 }
 
 BusModel::~BusModel()
-{
-
-}
+= default;
 
 void BusModel::ResetBus(rail_node_t *head)
 {