diff --git a/car.cpp b/car.cpp
index 4a33d00..9ddd668 100644
--- a/car.cpp
+++ b/car.cpp
@@ -221,6 +221,19 @@ QString Car::getFee() const
     if (m_status == waiting)
         return "0";
     int elapsed = startTime.msecsTo(QTime::currentTime());
+    switch (m_color) {
+    case Color::Pink:
+        elapsed *= 1;
+        break;
+    case Color::Red:
+        elapsed *= 2;
+        break;
+    case Color::Yellow:
+        elapsed *= 3;
+        break;
+    default:
+        break;
+    }
     return QString::number(elapsed / 1000);
 }
 
@@ -308,7 +321,9 @@ void Car::setPlateNumber(const QString &number) {
 void Car::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event)
 {
     if(m_status==parking&&event->button()==Qt::LeftButton)
-        emit out(this,-1);
+        emit out(this, -1);
+    else if (m_status == waiting && event->button() == Qt::LeftButton)
+        emit back(this);
     event->accept();
 }
 
diff --git a/carlist.cpp b/carlist.cpp
index 8fd74a3..45d7a8b 100644
--- a/carlist.cpp
+++ b/carlist.cpp
@@ -110,3 +110,12 @@ void Adapter::update()
     beginResetModel();
     endResetModel();
 }
+
+void sort(QList<Car*>::iterator s, QList<Car*>::iterator e,
+          std::function<bool (const Car *, const Car *)> comp)
+{
+    Q_UNUSED(s);
+    Q_UNUSED(e);
+    Q_UNUSED(comp);
+    return ;
+}
diff --git a/carlist.h b/carlist.h
index dedd445..8684264 100644
--- a/carlist.h
+++ b/carlist.h
@@ -8,6 +8,7 @@
 #include <QRunnable>
 #include <QAbstractTableModel>
 #include "car.h"
+#include <functional>
 
 namespace Ui {
 class CarList;
@@ -49,4 +50,7 @@ private:
     Ui::CarList *ui;
 };
 
+void sort(QList<Car*>::iterator s, QList<Car*>::iterator e,
+          std::function<bool (const Car*, const Car*)> comp);
+
 #endif // CARLIST_H
diff --git a/parkingLotManager.cpp b/parkingLotManager.cpp
index ed45dd2..f197be8 100644
--- a/parkingLotManager.cpp
+++ b/parkingLotManager.cpp
@@ -188,6 +188,38 @@ QPair<QString, int> ParkingLotManager::search(const QString& plate)
     return qMakePair(QString("-1"), -1);
 }
 
+bool comp2(const Car* c1, const Car* c2) {
+    return c1->getPlateNumber() < c2->getPlateNumber();
+}
+
+int comp(const QString& p1, const Car* c2) {
+    return strcmp(p1.toStdString().c_str(),  c2->getPlateNumber().toStdString().c_str());
+}
+
+QPair<QString, int> ParkingLotManager::biSearch(const QString &plate)
+{
+    sort(m_all_cars.begin(), m_all_cars.end(), &comp2);
+    int left = 0, right = m_all_cars.size(), mid = m_all_cars.size() / 2;
+    while (left != right) {
+        int flag = comp(plate, m_all_cars.at(mid));
+        if (flag == -1) {
+            right = mid;
+        } else if (flag == 1) {
+            left = mid;
+        } else if (flag == 0) {
+            Car* c = m_all_cars.at(mid);
+            if (c->getStatus() == Car::Status::parking ||
+                    c->getStatus() == Car::Status::moving)
+                return qMakePair(m_widgets.at(c->getTargetFloor())->getName(),
+                                 c->getNum());
+            else if (c->getStatus() == Car::Status::waiting)
+                return qMakePair(QString("0"), 0);
+        }
+        mid = (right + left) / 2;
+    }
+    return qMakePair(QString("-1"), -1);
+}
+
 void ParkingLotManager::showMode(bool enable)
 {
     if (enable)
@@ -284,7 +316,7 @@ void ParkingLotManager::requestIn(Car* car)
 void ParkingLotManager::leave(Car* car)
 {
     int l = car->getCurrentFloor();
-    Log::i(QString("有车离开，当前共有%1个空车位").arg(m_pool.size()));
+    Log::i(QString("有车离开，已产生费用%1元，当前共有%2个空车位").arg(car->getFee()).arg(m_pool.size()));
     callIn();
     car->hide();
     m_all_cars.removeOne(car);
diff --git a/parkingLotManager.h b/parkingLotManager.h
index d1dfc8d..cbd09bb 100644
--- a/parkingLotManager.h
+++ b/parkingLotManager.h
@@ -36,6 +36,7 @@ public:
     bool checkSame(const QString& plate);
     QString getParkingLotName(int pos);
     QPair<QString, int> search(const QString& plate);
+    QPair<QString, int> biSearch(const QString& plate);
     void showMode(bool enable);
 
 public slots: