完成了SCANDirection函数和SCANBTWQuery函数

src/controller.c

@@ -265,10 +265,64 @@ bus_query_t *SCANGetQuery(int direction)
 
 int SCANDirection(bus_query_t *query)
 {
-    return BUS_STOP;
+    if(query == NULL)
+    {
+        return BUS_STOP;
+    }   //如果没有请求，公交车停止
+
+    else
+    {
+        int clockwise = 0;
+        int counterclockwise = 0;   //用于顺，逆时针方向所经站台计数
+
+        /**
+         * 公交车当前所在位置
+         */
+        rail_node_t *now_position = the_bus->rail_node_pos;
+        /**
+         * 公交车应该前进的方向
+         */
+        rail_node_t *target_position = query->node;
+
+        rail_node_t *pos = now_position;
+        while (pos != target_position) //顺时针计数
+        {
+            clockwise++;
+            pos = pos->next_node;
+        }
+
+        pos = now_position;
+        while (pos != target_position) //逆时针计数
+        {
+            counterclockwise++;
+            pos = pos->last_node;
+        }
+        
+        if(clockwise <= counterclockwise)
+        {
+            return BUS_CLOCK_WISE;
+        }//若顺时针距离短(或顺逆相等)，公交车顺时针运行
+        else
+        {
+            return BUS_COUNTER_CLOCK_WISE;
+        }//若逆时针距离短，公交车逆时针运行
+    }
 }
 
 bus_query_t *SCANBTWQuery()
 {
+    rail_node_t *now_position = the_bus->rail_node_pos;
+    //获取公交车当前所在站点
+    bus_query_t *p = queries;
+    
+    while(p != NULL)
+    {
+        if(p->node == now_position)
+        {
+            return p; 
+        }
+        p = p->next_node;
+    }//遍历请求链表，判断是否有可以顺便处理的请求
+
     return NULL;
 }