Finished very good reference

src/main/java/ArrayListCombiner/ArrayListCombiner.java

@@ -1,5 +1,7 @@
 package ArrayListCombiner;
 
+import Employee.Employee;
+
 import java.util.ArrayList;
 
 /**
@@ -9,4 +11,12 @@ import java.util.ArrayList;
  * The second method should be called superCombiner and should use ? super E
  */
 public class ArrayListCombiner {
+
+    public static <E> void extendCombiner(ArrayList<E> first, ArrayList<? extends E> second) {
+        first.addAll(second);
+    }
+
+    public static <E> void superCombiner(ArrayList<? super E> first, ArrayList<E> second) {
+        first.addAll(second);
+    }
 }

src/main/java/MapFunc/MapFunc.java

@@ -9,4 +9,13 @@ import java.util.function.Function;
  */
 public class MapFunc {
 
+    public static <E,T> ArrayList<E> map(ArrayList<T> elements, Function<T,E> function){
+        ArrayList<E> arrayList =  new ArrayList<>();
+        for (int i = 0; i < elements.size() ; i++) {
+            T t = elements.get(i);
+           arrayList.add(function.apply(t));
+        }
+        return arrayList;
+    }
+
 }

src/main/java/Pair/Arrays.java

@@ -2,6 +2,7 @@ package Pair;
 
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.Comparator;
 
 /**
  * In here you must make firstLast, which will return a pair of the first element in the array list and the last
@@ -11,6 +12,42 @@ import java.util.Collections;
  * And a minmax method that returns a pair containing the largest and smallest items from the array list
  */
 public class Arrays {
-    public static <___> Pair<E> firstLast(ArrayList<___> a) {
+
+    public static <E extends Comparable> Pair firstLast(ArrayList<E> as) {
+        E min = as.get(0);
+        E max = as.get(as.size()-1);
+
+        System.out.println(min);
+        System.out.println(max);
+
+        return new Pair(min, max);
+    }
+
+    public static <E extends Comparable> Pair minMax(ArrayList<E> al) {
+        E min = al.get(0);
+        E max = al.get(1);
+
+        for (E e: al) {
+            if(e.compareTo(min) < 0){
+                min = e;
+            }
+            if(e.compareTo(max) > 0){
+                max = e;
+            }
+        }
+
+        return new Pair(max, min);
     }
+
+
+
+
+    public static <E extends Comparable> E min(ArrayList<E> al) {
+        return (E) minMax(al).min();
+    }
+
+    public static  <E extends Comparable> E  max(ArrayList<E> al) {
+        return (E) minMax(al).max();
+    }
+
 }

src/main/java/Pair/Pair.java

@@ -1,5 +1,7 @@
 package Pair;
 
+import java.util.Comparator;
+
 /**
  * You need to store two values of type `E`, set them in a constructor, and have the following methods,
  * getFirst
@@ -7,6 +9,37 @@ package Pair;
  * min -> returns the minimum of the pair
  * max -> returns the maximum of the pair
  */
-public class Pair {
+public class Pair <E extends Comparable> {
+
+    private E first;
+    private E second;
+
+    public Pair(E first, E second){
+        this.first  = first;
+        this.second = second;
+    }
+
+    public E getFirst() {
+        return this.first;
+    }
+
+    public E getSecond() {
+        return this.second;
+    }
+
+    public E min() {
+        if(this.first.compareTo(this.second) > 0){
+            return this.second;
+        } else {
+            return this.first;
+        }
+    }
 
+    public E max() {
+        if(this.first.compareTo(this.second) > 0) {
+            return this.first;
+        } else {
+            return this.second;
+        }
+    }
 }

src/main/java/StackArray/GenericStack.java

@@ -1,5 +1,7 @@
 package StackArray;
 
+import java.lang.reflect.Array;
+import java.util.ArrayList;
 import java.util.Arrays;
 
 /**
@@ -8,8 +10,49 @@ import java.util.Arrays;
  * @param <E>
  */
 public class GenericStack<E> {
+
     private E[] elements;
 
     public GenericStack() {
+        //elements = Arrays.copyOf(this.elements, this.elements.length + 1);
+        //elements = (E[])Array.newInstance(E, 0);
+        //elements = (E[]) Array.newInstance(this.elements.getClass().getComponentType(), 1);
+        elements = (E[]) new Object[0];
+    }
+
+    public boolean isEmpty() {
+        return elements.length == 0 ? true : false;
+    }
+
+    public void push(E foobar) {
+        elements = Arrays.copyOf(this.elements, this.elements.length + 1);
+        // shift right
+        for( int index =elements.length-2; index >= 0 ; index-- ) {
+            elements[index+1] = elements [index];
+        }
+        elements[0] = foobar;
+    }
+
+    public E pop() {
+        if(this.elements.length == 0){
+            throw new IndexOutOfBoundsException();
+        }
+        E[] newElements = Arrays.copyOf(this.elements, this.elements.length - 1);
+
+        E poped = this.elements[0];
+
+        int newArrayCounter = 0;
+
+        for(int i = 1; i < this.elements.length; i++){
+            newElements[newArrayCounter] = this.elements[i];
+            newArrayCounter++;
+        }
+
+        this.elements = newElements;
+
+        return poped;
+
+
+
     }
 }

src/main/java/StackArray/ObjectStack.java

@@ -1,5 +1,7 @@
 package StackArray;
 
+import com.sun.tools.javah.Gen;
+
 import java.util.Arrays;
 
 /**
@@ -10,7 +12,22 @@ import java.util.Arrays;
 public class ObjectStack<E> {
     private Object[] elements;
 
+    private GenericStack<Object> genericStack;
+
     public ObjectStack() {
+        genericStack =  new GenericStack<Object>();
+
+    }
+
+    public boolean isEmpty() {
+        return genericStack.isEmpty();
+    }
+
+    public void push(E foobar) {
+        genericStack.push(foobar);
+    }
 
+    public Object pop() {
+        return genericStack.pop();
     }
-}
+}

src/main/java/StackArrayList/Stack.java

@@ -7,10 +7,21 @@ import java.util.ArrayList;
  * If you pop on an empty stack, throw an IndexOutOfBoundsException.
  */
 public class Stack<E> {
-    private ArrayList elements;
+    private ArrayList<E> elements = new ArrayList<>();
 
 
-    public Stack(){
+    public Stack(){}
 
+    public boolean isEmpty() {
+        return elements.isEmpty();
+    }
+
+    public void push(E foobar) {
+        this.elements.add(0, foobar);
+
+    }
+
+    public E pop() {
+        return elements.remove(0);
     }
 }

src/main/java/Table/Entry.java

@@ -2,6 +2,8 @@ package Table;
 
 public class Entry<K, V> {
     private K key;
+
+
     private V value;
 
     public Entry(K key, V value) {
@@ -17,4 +19,8 @@ public class Entry<K, V> {
         return value;
     }
 
+    public void setValue(V value) {
+        this.value = value;
+    }
+
 }

src/main/java/Table/Table.java

@@ -10,8 +10,43 @@ import java.util.ArrayList;
  * Void return on `remove`.
  */
 public class Table<K, V> {
-    private ArrayList entries;
+    private ArrayList<Entry<K,V>> entries;
 
     public Table() {
+        entries = new ArrayList<Entry<K, V>>();
+    }
+
+    public V get(K foo) {
+        V value = null;
+        for (Entry entry: this.entries) {
+            if(entry.getKey().equals(foo)){
+                value = (V) entry.getValue();
+            }
+        }
+        return value;
+    }
+
+
+    public void put(K foo, V i) {
+        if(this.get(foo) == null){
+            Entry<K,V> entry = new Entry<K, V>(foo, i);
+            this.entries.add(entry);
+        } else {
+            for(Entry entry: this.entries){
+                if(entry.getKey().equals(foo)){
+                    entry.setValue(i);
+                    break;
+                }
+            }
+        }
+    }
+
+    public void remove(K foo) {
+        for (int i = 0; i < this.entries.size(); i++) {
+            if(this.entries.get(i).getKey().equals(foo)){
+                this.entries.remove(i);
+                break;
+            }
+        }
     }
 }

src/main/java/TableNested/TableNested.java

@@ -1,5 +1,8 @@
 package TableNested;
 
+
+import Table.Entry;
+
 import java.util.ArrayList;
 
 /**
@@ -8,4 +11,68 @@ import java.util.ArrayList;
  */
 public class TableNested<K, V> {
 
+    private class Entry<K, V> {
+        private K key;
+
+
+        private V value;
+
+        public Entry(K key, V value) {
+            this.key = key;
+            this.value = value;
+        }
+
+        public K getKey() {
+            return key;
+        }
+
+        public V getValue() {
+            return value;
+        }
+
+        public void setValue(V value) {
+            this.value = value;
+        }
+    }
+
+    private ArrayList<Entry<K,V>> entries;
+
+    public TableNested() {
+        entries = new ArrayList<Entry<K, V>>();
+    }
+
+    public V get(K foo) {
+        V value = null;
+        for (Entry entry: this.entries) {
+            if(entry.getKey().equals(foo)){
+                value = (V) entry.getValue();
+            }
+        }
+        return value;
+    }
+
+    public void put(K foo, V i) {
+        if(this.get(foo) == null){
+            Entry<K,V> entry = new Entry<K, V>(foo, i);
+            this.entries.add(entry);
+        } else {
+            for(Entry entry: this.entries){
+                if(entry.getKey().equals(foo)){
+                    entry.setValue(i);
+                    break;
+                }
+            }
+        }
+    }
+
+    public void remove(K foo) {
+        for (int i = 0; i < this.entries.size(); i++) {
+            if(this.entries.get(i).getKey().equals(foo)){
+                this.entries.remove(i);
+                break;
+            }
+        }
+    }
+
+
 }

src/test/java/ArrayListCombiner/ArrayListCombinerTest.java

@@ -9,40 +9,40 @@ import org.junit.Assert;
 import java.util.ArrayList;
 
 public class ArrayListCombinerTest {
-//    Employee foo = new Employee("FOO", 100);
-//    Manager bar = new Manager("BAR", 100);
-//    @Test
-//    public void testExtendCombiner() throws Exception {
-//        // Given an array list with employees
-//        ArrayList<Employee> first = new ArrayList<>();
-//        first.add(foo);
-//        // An an array list with managers
-//        ArrayList<Manager> second = new ArrayList<>();
-//        second.add(bar);
-//        // When  I combine them
-//        ArrayListCombiner.extendCombiner(first, second);
-//        // Then I should get an arrayList with both
-//        ArrayList<Employee> expected = new ArrayList<>();
-//        expected.add(foo);
-//        expected.add(bar);
-//        Assert.assertEquals(expected, first);
-//    }
-//
-//    @Test
-//    public void testSuperCombiner() throws Exception {
-//        // Given an array list with employees
-//        ArrayList<Employee> first = new ArrayList<>();
-//        first.add(foo);
-//        // An an array list with managers
-//        ArrayList<Manager> second = new ArrayList<>();
-//        second.add(bar);
-//        // When  I combine them
-//        ArrayListCombiner.superCombiner(first, second);
-//        // Then I should get an arrayList with both
-//        ArrayList<Employee> expected = new ArrayList<>();
-//        expected.add(foo);
-//        expected.add(bar);
-//        Assert.assertEquals(expected, first);
-//    }
+    Employee foo = new Employee("FOO", 100);
+    Manager bar = new Manager("BAR", 100);
+    @Test
+    public void testExtendCombiner() throws Exception {
+        // Given an array list with employees
+        ArrayList<Employee> first = new ArrayList<>();
+        first.add(foo);
+        // An an array list with managers
+        ArrayList<Manager> second = new ArrayList<>();
+        second.add(bar);
+        // When  I combine them
+        ArrayListCombiner.extendCombiner(first, second);
+        // Then I should get an arrayList with both
+        ArrayList<Employee> expected = new ArrayList<>();
+        expected.add(foo);
+        expected.add(bar);
+        Assert.assertEquals(expected, first);
+    }
+
+    @Test
+    public void testSuperCombiner() throws Exception {
+        // Given an array list with employees
+        ArrayList<Employee> first = new ArrayList<>();
+        first.add(foo);
+        // An an array list with managers
+        ArrayList<Manager> second = new ArrayList<>();
+        second.add(bar);
+        // When  I combine them
+        ArrayListCombiner.superCombiner(first, second);
+        // Then I should get an arrayList with both
+        ArrayList<Employee> expected = new ArrayList<>();
+        expected.add(foo);
+        expected.add(bar);
+        Assert.assertEquals(expected, first);
+    }
 
 }

src/test/java/MapFunc/MapFuncTest.java

@@ -1,36 +1,36 @@
-//package MapFunc;
-//
-//import MapFunc.MapFunc;
-//import org.junit.Test;
-//
-//import java.util.ArrayList;
-//import org.junit.Assert;
-//
-//public class MapFuncTest {
-//    @Test
-//    public void testSingleTypeMap() throws Exception {
-//        // Given an integer array list
-//        ArrayList<Integer> intList = new ArrayList<>();
-//        intList.add(1);
-//        intList.add(2);
-//        // When it's mapped with a function to double the value
-//        ArrayList<Integer> mappedList = MapFunc.map(intList, num -> num*2);
-//        // Then all the values are doubled
-//        Assert.assertEquals(new Integer(2), mappedList.get(0));
-//        Assert.assertEquals(new Integer(4), mappedList.get(1));
-//    }
-//
-//    @Test
-//    public void testMultipleTypeMap() throws Exception {
-//        // Given an integer array list
-//        ArrayList<Integer> intList = new ArrayList<>();
-//        intList.add(1);
-//        intList.add(2);
-//        // When it's mapped with to string
-//        ArrayList<String> mappedList = MapFunc.map(intList, num -> num.toString());
-//        // Then all the values are doubled
-//        Assert.assertEquals("1", mappedList.get(0));
-//        Assert.assertEquals("2", mappedList.get(1));
-//    }
-//
-//}
+package MapFunc;
+
+import MapFunc.MapFunc;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import org.junit.Assert;
+
+public class MapFuncTest {
+    @Test
+    public void testSingleTypeMap() throws Exception {
+        // Given an integer array list
+        ArrayList<Integer> intList = new ArrayList<>();
+        intList.add(1);
+        intList.add(2);
+        // When it's mapped with a function to double the value
+        ArrayList<Integer> mappedList = MapFunc.map(intList, num -> num*2);
+        // Then all the values are doubled
+        Assert.assertEquals(new Integer(2), mappedList.get(0));
+        Assert.assertEquals(new Integer(4), mappedList.get(1));
+    }
+
+    @Test
+    public void testMultipleTypeMap() throws Exception {
+        // Given an integer array list
+        ArrayList<Integer> intList = new ArrayList<>();
+        intList.add(1);
+        intList.add(2);
+        // When it's mapped with to string
+        ArrayList<String> mappedList = MapFunc.map(intList, num -> num.toString());
+        // Then all the values are doubled
+        Assert.assertEquals("1", mappedList.get(0));
+        Assert.assertEquals("2", mappedList.get(1));
+    }
+
+}

src/test/java/Pair/ArraysTest.java

@@ -1,74 +1,75 @@
-//package Pair;
-//
-//import org.junit.Assert;
-//import org.junit.Test;
-//
-//import java.util.ArrayList;
-//
-//public class ArraysTest {
-//    @Test
-//    public void firstLast() throws Exception {
-//        // Given an ArrayList of Integers
-//        ArrayList<Integer> al = new ArrayList<>();
-//        al.add(1);
-//        al.add(5);
-//        al.add(3);
-//        al.add(4);
-//        al.add(2);
-//        al.add(0);
-//        al.add(1000);
-//        // When firstLast is called
-//        Pair<Integer> result = Arrays.firstLast(al);
-//        // Then it should return the first and last items
-//        Assert.assertEquals(new Integer(1), result.getFirst());
-//        Assert.assertEquals(new Integer(1000), result.getSecond());
-//    }
-//
-//    @Test
-//    public void testMin() throws Exception {
-//        // Given an ArrayList of Integers
-//        ArrayList<Integer> al = new ArrayList<>();
-//        al.add(1);
-//        al.add(5);
-//        al.add(3);
-//        al.add(4);
-//        al.add(2);
-//        al.add(0);
-//        al.add(1000);
-//        // When min is called assert that it gets the smallest item
-//        Assert.assertEquals(new Integer(0), Arrays.min(al));
-//    }
-//
-//    @Test
-//    public void testMax() throws Exception {
-//        // Given an ArrayList of Integers
-//        ArrayList<Integer> al = new ArrayList<>();
-//        al.add(1);
-//        al.add(5);
-//        al.add(3);
-//        al.add(4);
-//        al.add(2);
-//        al.add(0);
-//        al.add(1000);
-//        // When min is called assert that it gets the largest item
-//        Assert.assertEquals(new Integer(1000), Arrays.max(al));
-//    }
-//
-//    @Test
-//    public void testMinMax() throws Exception {
-//        // Given an ArrayList of Integers
-//        ArrayList<Integer> al = new ArrayList<>();
-//        al.add(1);
-//        al.add(5);
-//        al.add(3);
-//        al.add(4);
-//        al.add(2);
-//        al.add(0);
-//        al.add(1000);
-//        // When minMax is called
-//        Pair<Integer> result = Arrays.minMax(al);
-//        // Then it should return the first and last items
-//        Assert.assertEquals(new Integer(0), result.min());
-//        Assert.assertEquals(new Integer(1000), result.max());
-//    }
-//}
+package Pair;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.ArrayList;
+
+public class ArraysTest {
+    @Test
+    public void firstLast() throws Exception {
+
+        // Given an ArrayList of Integers
+        ArrayList<Integer> al = new ArrayList<>();
+        al.add(1);
+        al.add(5);
+        al.add(3);
+        al.add(4);
+        al.add(2);
+        al.add(0);
+        al.add(1000);
+        // When firstLast is called
+        Pair<Integer> result = Arrays.firstLast(al);
+        // Then it should return the first and last items
+        Assert.assertEquals(new Integer(1), result.getFirst());
+        Assert.assertEquals(new Integer(1000), result.getSecond());
+    }
+
+    @Test
+    public void testMin() throws Exception {
+        // Given an ArrayList of Integers
+        ArrayList<Integer> al = new ArrayList<>();
+        al.add(1);
+        al.add(5);
+        al.add(3);
+        al.add(4);
+        al.add(2);
+        al.add(0);
+        al.add(1000);
+        // When min is called assert that it gets the smallest item
+        Assert.assertEquals(new Integer(0), Arrays.min(al));
+    }
+
+    @Test
+    public void testMax() throws Exception {
+        // Given an ArrayList of Integers
+        ArrayList<Integer> al = new ArrayList<>();
+        al.add(1);
+        al.add(5);
+        al.add(3);
+        al.add(4);
+        al.add(2);
+        al.add(0);
+        al.add(1000);
+        // When min is called assert that it gets the largest item
+        Assert.assertEquals(new Integer(1000), Arrays.max(al));
+    }
+
+    @Test
+    public void testMinMax() throws Exception {
+        // Given an ArrayList of Integers
+        ArrayList<Integer> al = new ArrayList<>();
+        al.add(1);
+        al.add(5);
+        al.add(3);
+        al.add(4);
+        al.add(2);
+        al.add(0);
+        al.add(1000);
+        // When minMax is called
+        Pair<Integer> result = Arrays.minMax(al);
+        // Then it should return the first and last items
+        Assert.assertEquals(new Integer(0), result.min());
+        Assert.assertEquals(new Integer(1000), result.max());
+    }
+}

src/test/java/Pair/PairTest.java

@@ -1,32 +1,32 @@
-//package Pair;
-//
-//import org.junit.Test;
-//import org.junit.Assert;
-//
-//public class PairTest {
-//
-//    @Test
-//    public void testGetters() throws Exception {
-//        // Given a pair with "Foo" and "Bar"
-//        Pair<String> p = new Pair<String>("Foo", "Bar");
-//        // When getFirst and getSecond are called, they should be returned.
-//        Assert.assertEquals("Foo", p.getFirst());
-//        Assert.assertEquals("Bar",  p.getSecond());
-//    }
-//
-//    @Test
-//    public void testMin() throws Exception {
-//        // Given a pair with two values
-//        Pair<Double> p = new Pair<Double>(1.23, 2.34);
-//        // When p.min() is called, the smallest should be returned.
-//        Assert.assertEquals(new Double(1.23), p.min());
-//    }
-//
-//    @Test
-//    public void testMax() throws Exception {
-//        // Given a pair with two values
-//        Pair<Double> p = new Pair<Double>(1.23, 2.34);
-//        // When p.max() is called, the largest should be returned.
-//        Assert.assertEquals(new Double(2.34), p.max());
-//    }
-//}
+package Pair;
+
+import org.junit.Test;
+import org.junit.Assert;
+
+public class PairTest {
+
+    @Test
+    public void testGetters() throws Exception {
+        // Given a pair with "Foo" and "Bar"
+        Pair<String> p = new Pair<String>("Foo", "Bar");
+        // When getFirst and getSecond are called, they should be returned.
+        Assert.assertEquals("Foo", p.getFirst());
+        Assert.assertEquals("Bar",  p.getSecond());
+    }
+
+    @Test
+    public void testMin() throws Exception {
+        // Given a pair with two values
+        Pair<Double> p = new Pair<Double>(1.23, 2.34);
+        // When p.min() is called, the smallest should be returned.
+        Assert.assertEquals(new Double(1.23), p.min());
+    }
+
+    @Test
+    public void testMax() throws Exception {
+        // Given a pair with two values
+        Pair<Double> p = new Pair<Double>(1.23, 2.34);
+        // When p.max() is called, the largest should be returned.
+        Assert.assertEquals(new Double(2.34), p.max());
+    }
+}

src/test/java/StackArray/GenericStackTest.java

@@ -1,41 +1,41 @@
-//package StackArray;
-//
-//import org.junit.Assert;
-//import org.junit.Test;
-//
-//public class GenericStackTest {
-//    @Test
-//    public void testPushingGrowsTheStack() throws Exception {
-//        // Given an empty stack
-//        GenericStack<String> stack = new GenericStack<>();
-//
-//        // Assert that it is empty.
-//        Assert.assertEquals(true, stack.isEmpty());
-//        // When we push something onto the stack
-//        stack.push("foobar");
-//        // Then it shouldn't be empty
-//        Assert.assertEquals(false, stack.isEmpty());
-//    }
-//
-//    @Test
-//    public void testPushingAndPoppingOrder() throws Exception {
-//        // Given an empty stack
-//        GenericStack<String> stack = new GenericStack<>();
-//        // When we push two elements on it
-//        stack.push("foo");
-//        stack.push("bar");
-//        // Then we should see them returned in the correct order
-//        Assert.assertEquals("bar", stack.pop());
-//        Assert.assertEquals("foo", stack.pop());
-//    }
-//
-//    @Test(expected = IndexOutOfBoundsException.class)
-//    public void testPopFirst() throws Exception {
-//        // Given an empty stack
-//        GenericStack<String> stack = new GenericStack<>();
-//        // When it's popped
-//        stack.pop();
-//        // Then we should get an exception
-//    }
-//
-//}
+package StackArray;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class GenericStackTest {
+    @Test
+    public void testPushingGrowsTheStack() throws Exception {
+        // Given an empty stack
+        GenericStack<String> stack = new GenericStack<>();
+
+        // Assert that it is empty.
+        Assert.assertEquals(true, stack.isEmpty());
+        // When we push something onto the stack
+        stack.push("foobar");
+        // Then it shouldn't be empty
+        Assert.assertEquals(false, stack.isEmpty());
+    }
+
+    @Test
+    public void testPushingAndPoppingOrder() throws Exception {
+        // Given an empty stack
+        GenericStack<String> stack = new GenericStack<>();
+        // When we push two elements on it
+        stack.push("foo");
+        stack.push("bar");
+        // Then we should see them returned in the correct order
+        Assert.assertEquals("bar", stack.pop());
+        Assert.assertEquals("foo", stack.pop());
+    }
+
+    @Test(expected = IndexOutOfBoundsException.class)
+    public void testPopFirst() throws Exception {
+        // Given an empty stack
+        GenericStack<String> stack = new GenericStack<>();
+        // When it's popped
+        stack.pop();
+        // Then we should get an exception
+    }
+
+}

src/test/java/StackArray/ObjectStackTest.java

@@ -1,39 +1,39 @@
-//package StackArray;
-//
-//import org.junit.Assert;
-//import org.junit.Test;
-//
-//public class ObjectStackTest {
-//    @Test
-//    public void testPushingGrowsTheStack() throws Exception {
-//        // Given an empty stack
-//        ObjectStack<String> stack = new ObjectStack<>();
-//        // Assert that it is empty.
-//        Assert.assertEquals(true, stack.isEmpty());
-//        // When we push something onto the stack
-//        stack.push("foobar");
-//        // Then it shouldn't be empty
-//        Assert.assertEquals(false, stack.isEmpty());
-//    }
-//
-//    @Test
-//    public void testPushingAndPoppingOrder() throws Exception {
-//        // Given an empty stack
-//        ObjectStack<String> stack = new ObjectStack<>();
-//        // When we push two elements on it
-//        stack.push("foo");
-//        stack.push("bar");
-//        // Then we should see them returned in the correct order
-//        Assert.assertEquals("bar", stack.pop());
-//        Assert.assertEquals("foo", stack.pop());
-//    }
-//
-//    @Test(expected = IndexOutOfBoundsException.class)
-//    public void testPopFirst() throws Exception {
-//        // Given an empty stack
-//        ObjectStack<String> stack = new ObjectStack<>();
-//        // When it's popped
-//        stack.pop();
-//        // Then we should get an exception
-//    }
-//}
+package StackArray;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class ObjectStackTest {
+    @Test
+    public void testPushingGrowsTheStack() throws Exception {
+        // Given an empty stack
+        ObjectStack<String> stack = new ObjectStack<>();
+        // Assert that it is empty.
+        Assert.assertEquals(true, stack.isEmpty());
+        // When we push something onto the stack
+        stack.push("foobar");
+        // Then it shouldn't be empty
+        Assert.assertEquals(false, stack.isEmpty());
+    }
+
+    @Test
+    public void testPushingAndPoppingOrder() throws Exception {
+        // Given an empty stack
+        ObjectStack<String> stack = new ObjectStack<>();
+        // When we push two elements on it
+        stack.push("foo");
+        stack.push("bar");
+        // Then we should see them returned in the correct order
+        Assert.assertEquals("bar", stack.pop());
+        Assert.assertEquals("foo", stack.pop());
+    }
+
+    @Test(expected = IndexOutOfBoundsException.class)
+    public void testPopFirst() throws Exception {
+        // Given an empty stack
+        ObjectStack<String> stack = new ObjectStack<>();
+        // When it's popped
+        stack.pop();
+        // Then we should get an exception
+    }
+}

src/test/java/StackArrayList/StackTest.java

@@ -1,45 +1,45 @@
-//package StackArrayList;
-//
-//import org.junit.Test;
-//
-//import org.junit.Assert;
-//
-//public class StackTest {
-//    @Test
-//    public void testEmptyStackStopsBeingEmptyWhenAnItemIsAdded() throws Exception {
-//        // Given an empty stack
-//        Stack<String> stack = new Stack<>();
-//        // Assert that it starts empty
-//        Assert.assertEquals(true, stack.isEmpty());
-//        // When an element gets pushed
-//        stack.push("foobar");
-//        // Then the stack should not be empty.
-//        Assert.assertEquals(false, stack.isEmpty());
-//    }
-//
-//    @Test
-//    public void testTwoItemsPushedComeOutInCorrectOrder() throws Exception {
-//        // Given an empty stack
-//        Stack<String> stack = new Stack<>();
-//
-//        //When two items are pushed
-//        stack.push("foo");
-//        stack.push("bar");
-//
-//        // Then they should come off in reverse order.
-//        Assert.assertEquals("bar", stack.pop());
-//        Assert.assertEquals("foo", stack.pop());
-//
-//        // And then the stack should be empty
-//        Assert.assertEquals(true, stack.isEmpty());
-//    }
-//
-//    @Test(expected = IndexOutOfBoundsException.class)
-//    public void testPopFirst() throws Exception {
-//        // Given an empty stack
-//        Stack<String> stack = new Stack<>();
-//        // Then it is popped
-//        stack.pop();
-//        // We should get an exception
-//    }
-//}
+package StackArrayList;
+
+import org.junit.Test;
+
+import org.junit.Assert;
+
+public class StackTest {
+    @Test
+    public void testEmptyStackStopsBeingEmptyWhenAnItemIsAdded() throws Exception {
+        // Given an empty stack
+        Stack<String> stack = new Stack<>();
+        // Assert that it starts empty
+        Assert.assertEquals(true, stack.isEmpty());
+        // When an element gets pushed
+        stack.push("foobar");
+        // Then the stack should not be empty.
+        Assert.assertEquals(false, stack.isEmpty());
+    }
+
+    @Test
+    public void testTwoItemsPushedComeOutInCorrectOrder() throws Exception {
+        // Given an empty stack
+        Stack<String> stack = new Stack<>();
+
+        //When two items are pushed
+        stack.push("foo");
+        stack.push("bar");
+
+        // Then they should come off in reverse order.
+        Assert.assertEquals("bar", stack.pop());
+        Assert.assertEquals("foo", stack.pop());
+
+        // And then the stack should be empty
+        Assert.assertEquals(true, stack.isEmpty());
+    }
+
+    @Test(expected = IndexOutOfBoundsException.class)
+    public void testPopFirst() throws Exception {
+        // Given an empty stack
+        Stack<String> stack = new Stack<>();
+        // Then it is popped
+        stack.pop();
+        // We should get an exception
+    }
+}

src/test/java/Swap/SwapTest.java

@@ -1,16 +1,16 @@
 package Swap;
-//
-//import org.junit.Assert;
-//import org.junit.Test;
-//
-///**
-// * Get the tests passing.
-// */
-//public class SwapTest {
-//    @Test
-//    public void testSwap() throws Exception {
-//        Double[] result = Swap.swap(0,1, 1.5, 2,3);
-//        Double[] expected = {2.0, 1.5, 3.0};
-//        Assert.assertArrayEquals(expected, result);
-//    }
-//}
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Get the tests passing.
+ */
+public class SwapTest {
+    @Test
+    public void testSwap() throws Exception {
+        Double[] result = Swap.swap(0,1, 1.5,2.0 ,3.0);
+        Double[] expected = {2.0, 1.5, 3.0};
+        Assert.assertArrayEquals(expected, result);
+    }
+}

src/test/java/Table/TableTest.java

@@ -1,50 +1,50 @@
-//package Table;
-//
-//import org.junit.Assert;
-//import org.junit.Test;
-//
-//public class TableTest {
-//    @Test
-//    public void testGetWithoutAnItemReturnsNull() throws Exception {
-//        // Given an empty table
-//        Table<String, Integer> table = new Table<String, Integer>();
-//        // When we try and get an item then it returns null
-//        Assert.assertEquals(table.get("foo"), null);
-//    }
-//
-//    @Test
-//    public void testPutAnItemReturnsAndDoesNotDelete() throws Exception {
-//        //Given an empty table
-//        Table<String, Integer> table = new Table<String, Integer>();
-//        // When we put an item in it
-//        table.put("foo", 1);
-//        // Then we should be able to get it's value
-//        Assert.assertEquals(table.get("foo"), new Integer(1));
-//        // And then we should be able to get it again as it wasn't removed
-//        Assert.assertEquals(table.get("foo"), new Integer(1));
-//    }
-//
-//    @Test
-//    public void testOverwritingAnItem() throws Exception {
-//        //Given an empty table
-//        Table<String, Integer> table = new Table<String, Integer>();
-//        // When we put an item in it
-//        table.put("foo", 1);
-//        // And we put a new value with the same key
-//        table.put("foo", 2);
-//        // Then we should get back the new value
-//        Assert.assertEquals(table.get("foo"), new Integer(2));
-//    }
-//
-//    @Test
-//    public void testRemoveAnItem() throws Exception {
-//        //Given an empty table
-//        Table<String, Integer> table = new Table<String, Integer>();
-//        // When we put an item in it
-//        table.put("foo", 1);
-//        // And we remove that item
-//        table.remove("foo");
-//        // Then we should get back null for that balue
-//        Assert.assertEquals(table.get("foo"), null);
-//    }
-//}
+package Table;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TableTest {
+    @Test
+    public void testGetWithoutAnItemReturnsNull() throws Exception {
+        // Given an empty table
+        Table<String, Integer> table = new Table<String, Integer>();
+        // When we try and get an item then it returns null
+        Assert.assertEquals(table.get("foo"), null);
+    }
+
+    @Test
+    public void testPutAnItemReturnsAndDoesNotDelete() throws Exception {
+        //Given an empty table
+        Table<String, Integer> table = new Table<String, Integer>();
+        // When we put an item in it
+        table.put("foo", 1);
+        // Then we should be able to get it's value
+        Assert.assertEquals(table.get("foo"), new Integer(1));
+        // And then we should be able to get it again as it wasn't removed
+        Assert.assertEquals(table.get("foo"), new Integer(1));
+    }
+
+    @Test
+    public void testOverwritingAnItem() throws Exception {
+        //Given an empty table
+        Table<String, Integer> table = new Table<String, Integer>();
+        // When we put an item in it
+        table.put("foo", 1);
+        // And we put a new value with the same key
+        table.put("foo", 2);
+        // Then we should get back the new value
+        Assert.assertEquals(table.get("foo"), new Integer(2));
+    }
+
+    @Test
+    public void testRemoveAnItem() throws Exception {
+        //Given an empty table
+        Table<String, Integer> table = new Table<String, Integer>();
+        // When we put an item in it
+        table.put("foo", 1);
+        // And we remove that item
+        table.remove("foo");
+        // Then we should get back null for that balue
+        Assert.assertEquals(table.get("foo"), null);
+    }
+}

src/test/java/TableNested/TableNestedTest.java

@@ -1,50 +1,50 @@
-//package TableNested;
-//
-//import org.junit.Assert;
-//import org.junit.Test;
-//
-//public class TableNestedTest {
-//    @Test
-//    public void testGetWithoutAnItemReturnsNull() throws Exception {
-//        // Given an empty table
-//        TableNested<String, Integer> table = new TableNested<String, Integer>();
-//        // When we try and get an item then it returns null
-//        Assert.assertEquals(table.get("foo"), null);
-//    }
-//
-//    @Test
-//    public void testPutAnItemReturnsAndDoesNotDelete() throws Exception {
-//        //Given an empty table
-//        TableNested<String, Integer> table = new TableNested<String, Integer>();
-//        // When we put an item in it
-//        table.put("foo", 1);
-//        // Then we should be able to get it's value
-//        Assert.assertEquals(table.get("foo"), new Integer(1));
-//        // And then we should be able to get it again as it wasn't removed
-//        Assert.assertEquals(table.get("foo"), new Integer(1));
-//    }
-//
-//    @Test
-//    public void testOverwritingAnItem() throws Exception {
-//        //Given an empty table
-//        TableNested<String, Integer> table = new TableNested<String, Integer>();
-//        // When we put an item in it
-//        table.put("foo", 1);
-//        // And we put a new value with the same key
-//        table.put("foo", 2);
-//        // Then we should get back the new value
-//        Assert.assertEquals(table.get("foo"), new Integer(2));
-//    }
-//
-//    @Test
-//    public void testRemoveAnItem() throws Exception {
-//        //Given an empty table
-//        TableNested<String, Integer> table = new TableNested<String, Integer>();
-//        // When we put an item in it
-//        table.put("foo", 1);
-//        // And we remove that item
-//        table.remove("foo");
-//        // Then we should get back null for that balue
-//        Assert.assertEquals(table.get("foo"), null);
-//    }
-//}
+package TableNested;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TableNestedTest {
+    @Test
+    public void testGetWithoutAnItemReturnsNull() throws Exception {
+        // Given an empty table
+        TableNested<String, Integer> table = new TableNested<String, Integer>();
+        // When we try and get an item then it returns null
+        Assert.assertEquals(table.get("foo"), null);
+    }
+
+    @Test
+    public void testPutAnItemReturnsAndDoesNotDelete() throws Exception {
+        //Given an empty table
+        TableNested<String, Integer> table = new TableNested<String, Integer>();
+        // When we put an item in it
+        table.put("foo", 1);
+        // Then we should be able to get it's value
+        Assert.assertEquals(table.get("foo"), new Integer(1));
+        // And then we should be able to get it again as it wasn't removed
+        Assert.assertEquals(table.get("foo"), new Integer(1));
+    }
+
+    @Test
+    public void testOverwritingAnItem() throws Exception {
+        //Given an empty table
+        TableNested<String, Integer> table = new TableNested<String, Integer>();
+        // When we put an item in it
+        table.put("foo", 1);
+        // And we put a new value with the same key
+        table.put("foo", 2);
+        // Then we should get back the new value
+        Assert.assertEquals(table.get("foo"), new Integer(2));
+    }
+
+    @Test
+    public void testRemoveAnItem() throws Exception {
+        //Given an empty table
+        TableNested<String, Integer> table = new TableNested<String, Integer>();
+        // When we put an item in it
+        table.put("foo", 1);
+        // And we remove that item
+        table.remove("foo");
+        // Then we should get back null for that balue
+        Assert.assertEquals(table.get("foo"), null);
+    }
+}