Lesson 7 Exercise 1

.idea/modules.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/AgileJava_Exercises.iml" filepath="$PROJECT_DIR$/AgileJava_Exercises.iml" />
+      <module fileurl="file://$PROJECT_DIR$/app/app.iml" filepath="$PROJECT_DIR$/app/app.iml" />
+    </modules>
+  </component>
+</project>
\ No newline at end of file

.idea/vcs.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file

app/src/main/java/com/example/paktalin/agilejava_exercises/Factorial.java

+package com.example.paktalin.agilejava_exercises;
+
+class Factorial {
+
+    static int getWhileFactorial(int number) {
+        int factorial;
+        if (number == 0 || number == 1)
+            factorial = 1;
+        else {
+            int increment = 1;
+            factorial = increment;
+            while (increment <= number) {
+                factorial *= increment;
+                increment++;
+            }
+        }
+        return factorial;
+    }
+
+    static int getDoWhileFactorial(int number) {
+        int factorial;
+        if (number == 0 || number == 1)
+            factorial = 1;
+        else {
+            int i = 1;
+            factorial = 1;
+            do {
+              factorial *= i;
+              i++;
+            } while (i <= number);
+        }
+        return factorial;
+    }
+
+    static int getForFactorial(int number) {
+        int factorial;
+        if (number == 0 || number == 1)
+            factorial = 1;
+        else {
+            factorial = 1;
+            for (int i = 1; i <= number; i++) {
+                factorial *= i;
+            }
+        }
+        return factorial;
+    }
+
+    static int getBreakFactorial(int number) {
+        int factorial;
+        if (number == 0 || number == 1)
+            factorial = 1;
+        else {
+            int i = 1;
+            factorial = 1;
+            while (true) {
+                if (i > number)
+                    break;
+                factorial *= i;
+                i++;
+            }
+        }
+        return factorial;
+    }
+}

app/src/test/java/com/example/paktalin/agilejava_exercises/AllTests.java

@@ -27,6 +27,8 @@ public class AllTests extends TestSuite {
         suite.addTestSuite(RookTest.class);
         suite.addTestSuite(KnightTest.class);
 
+        suite.addTestSuite(FactorialTest.class);
+
         return suite;
     }
 }

app/src/test/java/com/example/paktalin/agilejava_exercises/FactorialTest.java

+package com.example.paktalin.agilejava_exercises;
+
+import junit.framework.TestCase;
+
+public class FactorialTest extends TestCase {
+
+    public void testWhile() {
+        int factorial = Factorial.getWhileFactorial(5);
+        assertEquals(getFactorial(5), factorial);
+        factorial = Factorial.getWhileFactorial(4);
+        assertEquals(getFactorial(4), factorial);
+        factorial = Factorial.getWhileFactorial(3);
+        assertEquals(getFactorial(3), factorial);
+    }
+
+    public void testDoWhile() {
+        int factorial = Factorial.getDoWhileFactorial(5);
+        assertEquals(getFactorial(5), factorial);
+        factorial = Factorial.getDoWhileFactorial(4);
+        assertEquals(getFactorial(4), factorial);
+        factorial = Factorial.getDoWhileFactorial(3);
+        assertEquals(getFactorial(3), factorial);
+    }
+
+    public void testFor() {
+        int factorial = Factorial.getForFactorial(5);
+        assertEquals(getFactorial(5), factorial);
+        factorial = Factorial.getForFactorial(4);
+        assertEquals(getFactorial(4), factorial);
+        factorial = Factorial.getForFactorial(3);
+        assertEquals(getFactorial(3), factorial);
+    }
+
+    public void testBreak() {
+        int factorial = Factorial.getBreakFactorial(5);
+        assertEquals(getFactorial(5), factorial);
+        factorial = Factorial.getBreakFactorial(4);
+        assertEquals(getFactorial(4), factorial);
+        factorial = Factorial.getBreakFactorial(3);
+        assertEquals(getFactorial(3), factorial);
+    }
+
+    private int getFactorial(int number) {
+        int[] factorials = {1, 1, 2, 6, 24, 120};
+        return factorials[number];
+    }
+}