diff --git a/cell.cpp b/cell.cpp
index 31566fbace49b71ecc28f0460037e76ec00b6633..9fa90822afc9e36b5b536efbfc0e7955c05fa487 100644
--- a/cell.cpp
+++ b/cell.cpp
@@ -9,67 +9,67 @@
 
 Cell::Cell(QWidget *parent) : QWidget(parent)
 {
-    m_mapper = new QSignalMapper(this);
-    connect(m_mapper, SIGNAL(mapped(int)), this, SLOT(collapse(int)));
+    mapper = new QSignalMapper(this);
+    connect(mapper, SIGNAL(mapped(int)), this, SLOT(collapse(int)));
 
-    m_groupBox = new QGroupBox();
-    m_gridLayout = new QGridLayout();
+    groupBox = new QGroupBox();
+    gridLayout = new QGridLayout();
     setStyleSheet("border: 1px solid #1e282c; border-radius: 0px;background-color:#52585d;");
     for (char i = 0; i < 9; i++)
     {
-        m_states[i] = new QPushButton(QString::number(i + 1), this);
-        m_gridLayout->addWidget(m_states[i], i / 3, i % 3);
-        m_states[i]->setStyleSheet("border:none");
-        connect(m_states[i], SIGNAL(clicked()), m_mapper, SLOT(map()));
-        m_mapper->setMapping(m_states[i], i);
-        m_blocked[i] = 0;
+        states[i] = new QPushButton(QString::number(i + 1), this);
+        gridLayout->addWidget(states[i], i / 3, i % 3);
+        states[i]->setStyleSheet("border:none");
+        connect(states[i], SIGNAL(clicked()), mapper, SLOT(map()));
+        mapper->setMapping(states[i], i);
+        blocked[i] = 0;
     }
-    m_groupBox->setLayout(m_gridLayout);
-    m_number = new QPushButton(this);
+    groupBox->setLayout(gridLayout);
+    number = new QPushButton(this);
 
-    connect(m_number, SIGNAL(clicked()), this, SLOT(collapsedCellClicked()));
-    m_stackedWidget = new QStackedWidget(this);
-    m_stackedWidget->addWidget(m_groupBox);
-    m_stackedWidget->addWidget(m_number);
+    connect(number, SIGNAL(clicked()), this, SLOT(collapsedCellClicked()));
+    stackedWidget = new QStackedWidget(this);
+    stackedWidget->addWidget(groupBox);
+    stackedWidget->addWidget(number);
     setMinimumSize(70, 70);
 }
 
 void Cell::resizeEvent(QResizeEvent *event)
 {
     QWidget::resizeEvent(event);
-    m_stackedWidget->setFixedSize(this->size());
+    stackedWidget->setFixedSize(this->size());
     int smallest = this->width() < this->height() ? this->width() : this->height();
-    m_number->setStyleSheet("font-size:" + QString::number(smallest / 2) + "px;");
+    number->setStyleSheet("font-size:" + QString::number(smallest / 2) + "px;");
     return;
 }
 
 void Cell::collapse(int x)
 {
     collapsed = true;
-    m_stackedWidget->setCurrentIndex(1);
-    m_number->setText(QString::number(x + 1));
+    stackedWidget->setCurrentIndex(1);
+    number->setText(QString::number(x + 1));
     emit update(x);
 }
 void Cell::removeOption(int x)
 {
-    if (m_blocked[x] == 0)
+    if (blocked[x] == 0)
     {
-        m_states[x]->setText(" ");
-        m_states[x]->setDisabled(true);
+        states[x]->setText(" ");
+        states[x]->setDisabled(true);
         possibleStates--;
         options.erase(std::find(options.begin(), options.end(), x));
     }
-    m_blocked[x]++;
+    blocked[x]++;
 }
 
 void Cell::addOption(int x)
 {
-    m_blocked[x]--;
-    // if (!m_states[x]->isEnabled())
-    if (m_blocked[x] < 1)
+    blocked[x]--;
+    // if (!states[x]->isEnabled())
+    if (blocked[x] < 1)
     {
-        m_states[x]->setText(QString::number(x + 1));
-        m_states[x]->setDisabled(false);
+        states[x]->setText(QString::number(x + 1));
+        states[x]->setDisabled(false);
         possibleStates++;
         options.push_back(x);
     }
@@ -77,6 +77,6 @@ void Cell::addOption(int x)
 void Cell::collapsedCellClicked(void)
 {
     collapsed = false;
-    m_stackedWidget->setCurrentIndex(0);
-    emit undo(m_number->text().toInt() - 1);
+    stackedWidget->setCurrentIndex(0);
+    emit undo(number->text().toInt() - 1);
 }
\ No newline at end of file
diff --git a/cell.h b/cell.h
index 202b246622f844d7b38726cf758b4e149cc47904..1d1c53a51d313038cf338ea78018105ce2290e4f 100644
--- a/cell.h
+++ b/cell.h
@@ -18,13 +18,13 @@ public:
     std::vector<int> options = {0, 1, 2, 3, 4, 5, 6, 7, 8};
 
 private:
-    QSignalMapper *m_mapper;
-    QGroupBox *m_groupBox;
-    QGridLayout *m_gridLayout;
-    QPushButton *m_states[9];
-    QPushButton *m_number;
-    std::array<int, 9> m_blocked;
-    QStackedWidget *m_stackedWidget;
+    QSignalMapper *mapper;
+    QGroupBox *groupBox;
+    QGridLayout *gridLayout;
+    QPushButton *states[9];
+    QPushButton *number;
+    std::array<int, 9> blocked;
+    QStackedWidget *stackedWidget;
 
 signals:
     void update(int x);
diff --git a/window.cpp b/window.cpp
index 55e08c3c78f0e1a9f15a07d938bd700d7ab621f3..cfa471a6944298a28f9744d64b9b84505eb7ae62 100644
--- a/window.cpp
+++ b/window.cpp
@@ -13,35 +13,35 @@
 Window::Window(QWidget *parent)
     : QWidget{parent}
 {
-    m_solveButton = new QPushButton("solve", this);
-    connect(m_solveButton, SIGNAL(clicked()), this, SLOT(solveButtonClicked()));
-    m_clearButton = new QPushButton("Clear", this);
-    connect(m_clearButton, SIGNAL(clicked()), this, SLOT(clearButtonClicked()));
+    solveButton = new QPushButton("solve", this);
+    connect(solveButton, SIGNAL(clicked()), this, SLOT(solveButtonClicked()));
+    clearButton = new QPushButton("Clear", this);
+    connect(clearButton, SIGNAL(clicked()), this, SLOT(clearButtonClicked()));
 
-    m_slider = new QSlider(this);
-    m_slider->setRange(0, 1000);
-    m_slider->setOrientation(Qt::Horizontal);
-    m_slider->setValue(m_delay);
-    connect(m_slider, SIGNAL(valueChanged(int)), this, SLOT(setValue(int)));
+    slider = new QSlider(this);
+    slider->setRange(0, 1000);
+    slider->setOrientation(Qt::Horizontal);
+    slider->setValue(delayTime);
+    connect(slider, SIGNAL(valueChanged(int)), this, SLOT(setValue(int)));
 
-    m_horizontalLayout = new QHBoxLayout(this);
-    m_verticalLayout = new QVBoxLayout();
-    m_layout = new QGridLayout();
+    horizontalLayout = new QHBoxLayout(this);
+    verticalLayout = new QVBoxLayout();
+    layout = new QGridLayout();
 
-    m_spacer[0] = new QSpacerItem(4, 4, QSizePolicy::Minimum, QSizePolicy::Fixed);
-    m_spacer[1] = new QSpacerItem(4, 4, QSizePolicy::Minimum, QSizePolicy::Fixed);
-    m_spacer[2] = new QSpacerItem(8, 8, QSizePolicy::Minimum, QSizePolicy::Expanding);
-    m_verticalLayout->addItem(m_spacer[2]);
+    spacer[0] = new QSpacerItem(4, 4, QSizePolicy::Minimum, QSizePolicy::Fixed);
+    spacer[1] = new QSpacerItem(4, 4, QSizePolicy::Minimum, QSizePolicy::Fixed);
+    spacer[2] = new QSpacerItem(8, 8, QSizePolicy::Minimum, QSizePolicy::Expanding);
+    verticalLayout->addItem(spacer[2]);
 
-    m_verticalLayout->addWidget(m_solveButton);
-    m_verticalLayout->addWidget(m_slider);
-    m_verticalLayout->addWidget(m_clearButton);
-    m_horizontalLayout->addLayout(m_layout, 5);
-    m_horizontalLayout->addLayout(m_verticalLayout, 1);
+    verticalLayout->addWidget(solveButton);
+    verticalLayout->addWidget(slider);
+    verticalLayout->addWidget(clearButton);
+    horizontalLayout->addLayout(layout, 5);
+    horizontalLayout->addLayout(verticalLayout, 1);
 
-    m_layout->addItem(m_spacer[0], 3, 3);
-    m_layout->addItem(m_spacer[1], 7, 7);
-    m_layout->setSpacing(0);
+    layout->addItem(spacer[0], 3, 3);
+    layout->addItem(spacer[1], 7, 7);
+    layout->setSpacing(0);
 
     int dx = 0;
     int dy = 0;
@@ -49,16 +49,16 @@ Window::Window(QWidget *parent)
     {
         for (int y = 0; y < 9; y++)
         {
-            m_cell[x + y * 9].setParent(this);
-            m_layout->addWidget(&m_cell[x + y * 9], y + y / 3, x + x / 3);
+            cell[x + y * 9].setParent(this);
+            layout->addWidget(&cell[x + y * 9], y + y / 3, x + x / 3);
             // connecting signals & slots
             for (int d = 0; d < 9; d++) // rows and columns
             {
-                connect(&m_cell[x + y * 9], SIGNAL(update(int)), &m_cell[x + d * 9], SLOT(removeOption(int)));
-                connect(&m_cell[x + y * 9], SIGNAL(update(int)), &m_cell[d + y * 9], SLOT(removeOption(int)));
+                connect(&cell[x + y * 9], SIGNAL(update(int)), &cell[x + d * 9], SLOT(removeOption(int)));
+                connect(&cell[x + y * 9], SIGNAL(update(int)), &cell[d + y * 9], SLOT(removeOption(int)));
 
-                connect(&m_cell[x + y * 9], SIGNAL(undo(int)), &m_cell[x + d * 9], SLOT(addOption(int)));
-                connect(&m_cell[x + y * 9], SIGNAL(undo(int)), &m_cell[d + y * 9], SLOT(addOption(int)));
+                connect(&cell[x + y * 9], SIGNAL(undo(int)), &cell[x + d * 9], SLOT(addOption(int)));
+                connect(&cell[x + y * 9], SIGNAL(undo(int)), &cell[d + y * 9], SLOT(addOption(int)));
             }
             int a = x / 3 * 3;
             int b = y / 3 * 3;
@@ -68,9 +68,9 @@ Window::Window(QWidget *parent)
                 {
                     if (x1 == x || y1 == y)
                         continue;
-                    connect(&m_cell[x + y * 9], SIGNAL(update(int)), &m_cell[x1 + y1 * 9], SLOT(removeOption(int)));
+                    connect(&cell[x + y * 9], SIGNAL(update(int)), &cell[x1 + y1 * 9], SLOT(removeOption(int)));
 
-                    connect(&m_cell[x + y * 9], SIGNAL(undo(int)), &m_cell[x1 + y1 * 9], SLOT(addOption(int)));
+                    connect(&cell[x + y * 9], SIGNAL(undo(int)), &cell[x1 + y1 * 9], SLOT(addOption(int)));
                 }
             }
         }
@@ -85,7 +85,7 @@ void Window::solveButtonClicked()
     while (1)
     {
         repaint(); // draw cells again
-        delay(m_delay);
+        delay(delayTime);
         if (backtracking)
         {
             hist.back().cell->collapsedCellClicked();
@@ -97,7 +97,7 @@ void Window::solveButtonClicked()
             backtracking = false;
             int choiceNr = rand() % hist.back().options.size(); // choose a random number;
             repaint();                                         // draw cells again
-            delay(m_delay);
+            delay(delayTime);
             hist.back().cell->collapse(hist.back().options[choiceNr]); // collapse cell with chosen number;
             std::vector<int>::iterator it;
             it = hist.back().options.begin() + choiceNr;
@@ -111,17 +111,17 @@ void Window::solveButtonClicked()
             {
                 for (int y = 0; y < 9; y++)
                 {
-                    if (m_cell[x + y * 9].collapsed)
+                    if (cell[x + y * 9].collapsed)
                         continue;
-                    else if (m_cell[x + y * 9].possibleStates < minEtropy)
+                    else if (cell[x + y * 9].possibleStates < minEtropy)
                     {
-                        minEtropy = m_cell[x + y * 9].possibleStates;
+                        minEtropy = cell[x + y * 9].possibleStates;
                         b.clear();
-                        b.push_back(&m_cell[x + y * 9]);
+                        b.push_back(&cell[x + y * 9]);
                     }
-                    else if (m_cell[x + y * 9].possibleStates == minEtropy)
+                    else if (cell[x + y * 9].possibleStates == minEtropy)
                     {
-                        b.push_back(&m_cell[x + y * 9]);
+                        b.push_back(&cell[x + y * 9]);
                     }
                 }
             }
@@ -154,7 +154,7 @@ inline void Window::delay(int millisecondsWait)
 }
 void Window::clearButtonClicked()
 {
-    for (auto &x : m_cell)
+    for (auto &x : cell)
     {
         if (x.collapsed)
             x.collapsedCellClicked();
@@ -163,6 +163,6 @@ void Window::clearButtonClicked()
 }
 void Window::setValue(int s)
 {
-    m_delay = s;
+    delayTime = s;
     return;
 }
\ No newline at end of file
diff --git a/window.h b/window.h
index 51373e4c7141db8ccbe7745fad83e3fbdafcbf28..3fc7c089ce078490e47788f9e955b6bf6efb0b60 100644
--- a/window.h
+++ b/window.h
@@ -16,15 +16,15 @@ public:
     explicit Window(QWidget *parent = nullptr);
 
 private:
-    QPushButton *m_clearButton;
-    QPushButton *m_solveButton;
-    QSlider *m_slider;
-    std::array<Cell, 81> m_cell;
-    int m_delay = 300;
-    QSpacerItem *m_spacer[3];
-    QHBoxLayout *m_horizontalLayout;
-    QVBoxLayout *m_verticalLayout;
-    QGridLayout *m_layout;
+    QPushButton *clearButton;
+    QPushButton *solveButton;
+    QSlider *slider;
+    std::array<Cell, 81> cell;
+    int delayTime = 300;
+    QSpacerItem *spacer[3];
+    QHBoxLayout *horizontalLayout;
+    QVBoxLayout *verticalLayout;
+    QGridLayout *layout;
     struct History
     {
         Cell *cell;