Adding another activity for lesson 1

Author: cutajarj

src/main/java/com/packt/datastructuresandalg/lesson1/activity/improveintersection/solution/FastInterstectionSol1.java

@@ -22,4 +22,12 @@ public List<Integer> intersectionFast(int[] a, int[] b) {
     private void mergeSort(int[] input) {
         Arrays.sort(input);
     }
+
+    public static void main(String[] args) {
+        int[] numbers1 = new int[]{66, 24, 75, 22, 12, 87};
+        int[] numbers2 = new int[]{32, 41, 98, 66, 39, 24};
+
+        List<Integer> result = new FastInterstectionSol1().intersectionFast(numbers1, numbers2);
+        System.out.println(result);
+    }
 }

src/main/java/com/packt/datastructuresandalg/lesson1/activity/improveintersection/solution/FastInterstectionSol2.java

@@ -25,4 +25,13 @@ public List<Integer> intersectionFast(int[] a, int[] b) {
     public void mergeSort(int[] input) {
         Arrays.sort(input);
     }
+
+    public static void main(String[] args) {
+        int[] numbers1 = new int[]{66, 24, 75, 22, 12, 87};
+        int[] numbers2 = new int[]{32, 41, 98, 66, 39, 24};
+
+        List<Integer> result = new FastInterstectionSol2().intersectionFast(numbers1, numbers2);
+        System.out.println(result);
+    }
+
 }

src/main/java/com/packt/datastructuresandalg/lesson1/activity/octaltodecimal/OctalToDecimal.java

@@ -0,0 +1,7 @@
+package com.packt.datastructuresandalg.lesson1.activity.octaltodecimal;
+
+public class OctalToDecimal {
+    public int convertToDecimal(String octal) {
+        return 999;
+    }
+}

src/main/java/com/packt/datastructuresandalg/lesson1/activity/octaltodecimal/solution/OctalToDecimal.java

@@ -0,0 +1,20 @@
+package com.packt.datastructuresandalg.lesson1.activity.octaltodecimal.solution;
+
+public class OctalToDecimal {
+    public int convertToDecimal(String oct) {
+        int result = 0;
+        for (int i = 1; i <= oct.length(); i++) {
+            int octDigit = Integer.parseInt(oct.charAt(oct.length() - i) + "");
+            result += Math.pow(8, i - 1) * octDigit;
+        }
+        return result;
+    }
+
+    public static void main(String args[]) {
+        OctalToDecimal octalToDecimal = new OctalToDecimal();
+        System.out.println(octalToDecimal.convertToDecimal("17"));
+        System.out.println(octalToDecimal.convertToDecimal("72625"));
+        System.out.println(octalToDecimal.convertToDecimal("1"));
+        System.out.println(octalToDecimal.convertToDecimal("55142"));
+    }
+}

src/test/java/com/packt/datastructuresandalg/lesson1/activity/octaltodecimal/OctalToDecimalTest.java

@@ -0,0 +1,35 @@
+package com.packt.datastructuresandalg.lesson1.activity.octaltodecimal;
+
+import junit.framework.TestCase;
+
+public class OctalToDecimalTest extends TestCase {
+    public void testZeroOctal() {
+        OctalToDecimal octalToDecimal = new OctalToDecimal();
+        assertEquals(octalToDecimal.convertToDecimal("0"), 0);
+    }
+
+    public void testOneOctal() {
+        OctalToDecimal octalToDecimal = new OctalToDecimal();
+        assertEquals(octalToDecimal.convertToDecimal("1"), 1);
+    }
+
+    public void testFiveOctal() {
+        OctalToDecimal octalToDecimal = new OctalToDecimal();
+        assertEquals(octalToDecimal.convertToDecimal("5"), 5);
+    }
+
+    public void test17Octal() {
+        OctalToDecimal octalToDecimal = new OctalToDecimal();
+        assertEquals(octalToDecimal.convertToDecimal("17"), 15);
+    }
+
+    public void test72625Octal() {
+        OctalToDecimal octalToDecimal = new OctalToDecimal();
+        assertEquals(octalToDecimal.convertToDecimal("72625"), 30101);
+    }
+
+    public void test55142Octal() {
+        OctalToDecimal octalToDecimal = new OctalToDecimal();
+        assertEquals(octalToDecimal.convertToDecimal("55142"), 23138);
+    }
+}