recursive fibonacci implemented in TasksFrame

src/main/java/src/TasksFrame.java

@@ -64,6 +64,8 @@ public class TasksFrame extends JFrame {
 
     public void run() {
 
+        setupFib();
+
         setupHelloWorld();
 
         setupDate();
@@ -107,7 +109,59 @@ public class TasksFrame extends JFrame {
         setupBmi();
 
         setupReverse();
+    }
+
+    private void setupFib() {
+        JPanel jPanel = setupPanel("Fibonacci");
+
+        JTextField input = new JTextField();
+        input.setBounds(5, 60, 50, 30);
+        input.setVisible(true);
+        jPanel.add(input);
 
+        JTextField output = new JTextField();
+        output.setBounds(5, 100, 200, 30);
+        output.setVisible(true);
+        jPanel.add(output);
+
+        JButton button = new JButton("Calculate Fibonacci");
+        button.setBounds(70, 60, 150, 30);
+        button.setVisible(true);
+        jPanel.add(button);
+        button.addActionListener(new ActionListener() {
+            @Override
+            public void actionPerformed(ActionEvent e) {
+                output.setText("");
+                Integer n = Integer.valueOf(input.getText());
+                int[] a = new int[n+1];
+                recursiveFibonacci(a, n);
+
+                StringBuffer stringBuffer = new StringBuffer();
+                for (int i = 0; i < a.length; i++) {
+                    stringBuffer.append(a[i]);
+                    if (i==a.length-1) {
+                        stringBuffer.append("");
+                    } else {
+                        stringBuffer.append(", ");
+                    }
+                }
+                output.setText(stringBuffer.toString());
+            }
+        });
+    }
+
+    public int recursiveFibonacci(int[] a, int n) {
+        if (n == 0) {
+            a[n] = 0;
+            return 0;
+        } else if (n == 1) {
+            a[n] = 1;
+            return 1;
+        } else {
+            int i = recursiveFibonacci(a, n - 1) + recursiveFibonacci(a, n-2);
+            a[n] = i;
+            return a[n];
+        }
     }
 
     private void setupReverse() {

src/test/java/src/TasksFrameTest.java

@@ -7,6 +7,15 @@ import static org.junit.jupiter.api.Assertions.*;
 
 class TasksFrameTest {
 
+    @Test
+    void test_recursiveFib() {
+        TasksFrame tasksFrame = new TasksFrame();
+        int[] ints = new int[10 + 1];
+        tasksFrame.recursiveFibonacci(ints, 10);
+
+        assertArrayEquals(new int[]{0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55}, ints);
+    }
+
     @Test
     void bin1() {
         TasksFrame tasksFrame = new TasksFrame();