P41 i.e. 2.11 done for Java

shekhargulati · shekhargulati · commit 9b74a61964d2 · 2016-02-13T15:12:03.000+05:30
diff --git a/java8/README.md b/java8/README.md
@@ -694,3 +694,21 @@ public void phiOf99Is60() throws Exception {
     assertThat(p, equalTo(60));
 }
 ```
+
+### [P41](https://github.com/shekhargulati/99-problems/blob/master/java8/src/main/java/com/shekhargulati/ninetynine_problems/java8/_02_arithmetic/P41.java) **(*)  Compare the two methods of calculating Euler's totient function.**
+
+Use the solutions of problems P39 and P40 to compare the algorithms. Take the number of logical inferences as a measure for efficiency. Try to calculate `phi(10090)` as an example.
+
+```java
+@Test
+public void shouldCalculatePhiOf10090UsingP39() throws Exception {
+    long p = P39.phi(10090);
+    assertThat(p, equalTo(4032L));
+}
+
+@Test
+public void shouldCalculatePhiOf10090UsingP40() throws Exception {
+    long p = P40.phi(10090);
+    assertThat(p, equalTo(4032L));
+}
+```
diff --git a/java8/src/main/java/com/shekhargulati/ninetynine_problems/java8/_02_arithmetic/P41.java b/java8/src/main/java/com/shekhargulati/ninetynine_problems/java8/_02_arithmetic/P41.java
@@ -0,0 +1,8 @@
+package com.shekhargulati.ninetynine_problems.java8._02_arithmetic;
+
+/**
+ * (*) Compare the two methods of calculating Euler's totient function.
+ * Check P41Test
+ */
+public class P41 {
+}
diff --git a/java8/src/test/java/com/shekhargulati/ninetynine_problems/java8/_02_arithmetic/P41Test.java b/java8/src/test/java/com/shekhargulati/ninetynine_problems/java8/_02_arithmetic/P41Test.java
@@ -0,0 +1,21 @@
+package com.shekhargulati.ninetynine_problems.java8._02_arithmetic;
+
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.junit.Assert.assertThat;
+
+public class P41Test {
+
+    @Test
+    public void shouldCalculatePhiOf10090UsingP39() throws Exception {
+        long p = P39.phi(10090);
+        assertThat(p, equalTo(4032L));
+    }
+
+    @Test
+    public void shouldCalculatePhiOf10090UsingP40() throws Exception {
+        long p = P40.phi(10090);
+        assertThat(p, equalTo(4032L));
+    }
+}
