add precompiled header

+#include "stdafx.h"
 #include "EdgeItem.h"
-#include <QtWidgets>
 
 void EdgeItem::mousePressEvent(QGraphicsSceneMouseEvent * event)
 {

 #ifndef EDGEITEM_H
 #define EDGEITEM_H
 
-#include <QColor>
-#include <QGraphicsItem>
+#include "stdafx.h"
 
 
 class EdgeItem

+#include "stdafx.h"
 #include "GraphItem.h"
 
-#include <boost/graph/fruchterman_reingold.hpp>
-#include <boost/graph/random_layout.hpp>
-#include <boost/graph/circle_layout.hpp>
-#include <boost/graph/dijkstra_shortest_paths.hpp>
-#include <boost/algorithm/string.hpp>	//boost::split
-#include <boost/bimap.hpp>
-#include <boost/regex.hpp>
-
-#include <exception>
-#include <iterator>
-#include <string>
-#include <map>
-#include <vector>
-
-#include <QDebug>
-#include <QtWidgets>
-
-
 GraphItem::GraphItem(ifstream& fin)
 {
 	if (!fin)
@@ -270,6 +253,13 @@ void GraphItem::path_highlighting(std::string start, std::string end)
 	
 }
 
+void GraphItem::reset_color()
+{
+	for (auto& n: nodeList) {
+		n->setColor(QColor());
+	}
+}
+
 //event handler
 void GraphItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
 {

 #ifndef GRAPHITEM_H
 #define GRAPHITEM_H
 
-#include <QGraphicsItem>
-#include <QList>
-#include <QColor>
-
-#include <boost/graph/adjacency_list.hpp>
-#include <boost/graph/topology.hpp>
-#include <boost/graph/graph_traits.hpp>
-
-#include <fstream>
-
+#include "stdafx.h"
 #include "NodeItem.h"
 #include "EdgeItem.h"
 
@@ -68,6 +59,7 @@ public:
 
 	//methods
 	void path_highlighting(std::string start, std::string end);
+	void reset_color();
 	//
 
 protected:

+#include "stdafx.h"
 #include "GraphicsView.h"
-#include <qmath.h>
-#include <QKeyEvent>
 
 //View
 View::View(const QString& name, QWidget *parent)

 #ifndef GRAPHICSVIEW_H
 #define GRAPHICSVIEW_H
 
-#include <QFrame>
-#include <QGraphicsView>
-#include <QGridLayout>
+#include "stdafx.h"
 
 //pre-declare
 class View;
 
-
 class GraphicsView
 	: public QGraphicsView
 {

+#include "stdafx.h"
 #include "MainWindow.h"
 
 MainWindow::MainWindow(QWidget *parent)

 #ifndef MAINWINDOW_H
 #define MAINWINDOW_H
 
-#include <QMainWindow>
-#include <QtWidgets>
-#include <QGridLayout>
-#include <QtGui>
-
-#include <iostream>
-
+#include "stdafx.h"
 //#include "ui_MainWindow.h"
 #include "PaperGraphWidget.h"
 

+#include "stdafx.h"
 #include "NodeItem.h"
-#include <QtWidgets>
-#include <QMessageBox>
 
 void NodeItem::mousePressEvent(QGraphicsSceneMouseEvent * event)
 {

 #ifndef NODEITEM_H
 #define NODEITEM_H
 
-#include <QColor>
-#include <QGraphicsItem>
-
+#include "stdafx.h"
 
 const int NODE_SIZE = 4;
 

@@ -33,6 +33,9 @@
       <Extensions>cpp;moc</Extensions>
       <SourceControlFiles>False</SourceControlFiles>
     </Filter>
+    <Filter Include="PCH">
+      <UniqueIdentifier>{23e088fd-f255-4f93-9c5e-f963b79d7a97}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="main.cpp">
@@ -77,6 +80,9 @@
     <ClCompile Include="GeneratedFiles\Release\moc_MainWindow.cpp">
       <Filter>Generated Files\Release</Filter>
     </ClCompile>
+    <ClCompile Include="stdafx.cpp">
+      <Filter>PCH</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <CustomBuild Include="PaperGraphWidget.h">
@@ -114,5 +120,8 @@
     <ClInclude Include="GeneratedFiles\ui_MainWindow.h">
       <Filter>Generated Files</Filter>
     </ClInclude>
+    <ClInclude Include="stdafx.h">
+      <Filter>PCH</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>
\ No newline at end of file

+#include "stdafx.h"
 #include "PaperGraphWidget.h"
 #include "NodeItem.h"
 #include "GraphicsView.h"
 
-#include <string>
-#include <QComboBox>
-#include <QMessageBox>
-#include <QtGui>
-
 PaperGraphWidget::PaperGraphWidget(QWidget *parent)
 	: QWidget(parent)
 {

 #ifndef PAPERGRAPHWIDGET_H
 #define PAPERGRAPHWIDGET_H
 
-#include <QtWidgets/QWidget>
-#include <QGraphicsScene>
-
-#include <fstream>
+#include "stdafx.h"
 
 #include "GraphItem.h"
 //#include "ui_PaperGraphWidget.h"
 
-
 class PaperGraphWidget : public QWidget
 {
 	Q_OBJECT

+#include "stdafx.h"
 #include "PaperGraphWidget.h"
 #include "MainWindow.h"
 
-#include <QtWidgets/QApplication>
-#include <QDebug>
-
-#include <algorithm>
-#include <exception>
-#include <fstream>
-#include <iterator>
-#include <string>
-#include <map>
-#include <vector>
-
-#include <boost/graph/fruchterman_reingold.hpp>
-//#include <boost/graph/kamada_kawai_spring_layout.hpp>
-#include <boost/graph/random_layout.hpp>
-#include <boost/graph/circle_layout.hpp>
-#include <boost/algorithm/string.hpp>	//boost::split
-#include <boost/bimap.hpp>
-
-using namespace std;
-
 /**
  *	Constants
  */

+#include "stdafx.h"

+#pragma once
+#include <QColor>
+#include <QComboBox>
+#include <QDebug>
+#include <QFrame>
+#include <QGraphicsItem>
+#include <QGraphicsScene>
+#include <QGraphicsView>
+#include <QGridLayout>
+#include <QKeyEvent>
+#include <QList>
+#include <QMainWindow>
+#include <qmath.h>
+#include <QMessageBox>
+#include <QtGui>
+#include <QtWidgets/QApplication>
+#include <QtWidgets/QWidget>
+#include <QtWidgets>
+
+#include <boost/algorithm/string.hpp>	//boost::split
+#include <boost/bimap.hpp>
+#include <boost/graph/adjacency_list.hpp>
+#include <boost/graph/circle_layout.hpp>
+#include <boost/graph/dijkstra_shortest_paths.hpp>
+#include <boost/graph/fruchterman_reingold.hpp>
+#include <boost/graph/graph_traits.hpp>
+#include <boost/graph/random_layout.hpp>
+#include <boost/graph/topology.hpp>
+#include <boost/regex.hpp>
+
+#include <algorithm>
+#include <exception>
+#include <fstream>
+#include <iostream>
+#include <iterator>
+#include <map>
+#include <string>
+#include <vector>
+
+using namespace boost;
+using namespace std;
\ No newline at end of file