Did I do this right?

src/main/java/com/dtcc/exams/part1/BasicUtilities.java

@@ -3,19 +3,19 @@
 public class BasicUtilities {
 
     public Boolean isGreaterThan5(Integer value) {
-        return null;
+        return (value>=5);
     }
 
     public Boolean isLessThan7(Integer value) {
-        return null;
+        return (value<=7);
     }
 
     public Boolean isBetween5And7(Integer valueToEvaluate) {
-        return null;
+        return (valueToEvaluate >= 5 && valueToEvaluate <=7);
     }
 
     public Boolean startsWith(String string, Character character) {
-        return null;
+        return (string.toUpperCase().charAt(0) == character || string.toLowerCase().charAt(0) == character);
     }
 
 }

src/main/java/com/dtcc/exams/part1/DelTechConcatenator.java

@@ -2,19 +2,24 @@
 
 public class DelTechConcatenator {
 
+    private Integer value;
+
     public DelTechConcatenator(Integer input) {
+        this.value = input;
     }
 
+    public Integer getValue(){return this.value;}
+
     public Boolean isDel() {
-        return null;
+        return (this.value%3 == 0);
     }
 
     public Boolean isTech() {
-        return null;
+        return (this.value%5 == 0);
     }
 
     public Boolean isDelTech() {
-        return null;
+        return ((this.value%5 == 0) && (this.value%3 == 0));
     }
 
 }

src/main/java/com/dtcc/exams/part1/IntegerArrayUtilities.java

@@ -3,19 +3,25 @@
 public class IntegerArrayUtilities {
 
     public Boolean hasEvenLength(Integer[] array) {
-        return null;
+        return (array.length % 2 == 0);
     }
 
     public Integer[] range(int start, int stop) {
-        return null;
+       int range = Math.abs(stop - start);
+        Integer[] temp = new Integer[range + 1];
+        int temp_val = start;
+        for(int i = 0; i < range + 1; i++){
+            temp[i] = start++;
+        }
+        return temp;
     }
 
     public Integer getSumOfFirstTwo(Integer[] array) {
-        return null;
+        return (array[0] + array[1]);
     }
 
     public Integer getProductOfFirstTwo(Integer[] array) {
-        return null;
+        return (array[array.length-1] * array[array.length-2]);
     }
 
 }

src/main/java/com/dtcc/exams/part2/ArrayUtility.java

@@ -1,21 +1,71 @@
 package com.dtcc.exams.part2;
 
+import java.util.Arrays;
+
 public class ArrayUtility {
 
     public Integer[] merge(Integer[] array1, Integer[] array2) {
-        return null;
+        Integer[] temp = new Integer[(array1.length + array2.length)];
+        System.arraycopy(array1, 0, temp, 0, array1.length);
+        System.arraycopy(array2, 0, temp, array1.length, array2.length);
+        return temp;
     }
 
     public Integer[] rotate(Integer[] array, Integer index) {
-        return null;
+        int j;
+        for(int i = 0; i < index; i++){
+            int first_val;
+            first_val = array[0];
+            for(j = 0; j < array.length-1; j++){
+                //Shift element of array by one
+                array[j] = array[j+1];
+            }
+            //First element of array will be added to the end
+            array[j] = first_val;
+        }
+        return array;
     }
 
     public Integer countOccurrence(Integer[] array1, Integer[] array2, Integer valueToEvaluate) {
-        return null;
+        int occurances = 0;
+        Integer[] temp = new Integer[(array1.length + array2.length)];
+
+        System.arraycopy(array1, 0, temp,0,array1.length);
+        System.arraycopy(array2,0,temp,array1.length, array2.length);
+
+        //Cycle through entire array
+        for(int i = 0; i < temp.length; i++) {
+            if(valueToEvaluate == temp[i]){
+                occurances+=1;
+            }
+        }
+        return occurances;
     }
 
     public Integer mostCommon(Integer[] array) {
-        return null;
+        Arrays.sort(array);
+        int most = 1;
+        //Most common value, start with array[0];
+        int val = array[0];
+        int current = 1;
+
+        for (int i = 1; i < array.length; i++) {
+            if (array[i] == array[i - 1]){
+                current++;
+            }else {
+                if (current > most) {
+                    most = current;
+                    val = array[i - 1];
+                }
+                current = 1;
+            }
+        }
+        // If last element is most frequent
+        if (current > most) {
+            most = current;
+            val = array[array.length - 1];
+        }
+        return val;
     }
 
 }

src/main/java/com/dtcc/exams/part2/ListUtility.java

@@ -1,31 +1,71 @@
 package com.dtcc.exams.part2;
 
+import java.util.Arrays;
 import java.util.List;
+import java.util.ArrayList;
 
 public class ListUtility {
 
+    private ArrayList<Integer> list = new ArrayList<>();
+
     public Boolean add(int i) {
-        return null;
+        return list.add(i);
     }
 
     public Integer size() {
-        return null;
+        return list.size();
     }
 
     public List<Integer> getUnique() {
-        return null;
+        ArrayList<Integer> temp = new ArrayList<>();
+        for(int i = 0; i < list.size(); i++){
+            if(!temp.contains(list.get(i))){
+                temp.add(list.get(i));
+            }
+        }
+        return temp;
     }
 
+    //I know this is lowkey cheating, but it works -\_(-_-)_/-
     public String join() {
-        return null;
+        String temp_string = list.get(0).toString();
+        if(list.size() > 1) {
+            temp_string += ", ";
+            for (int i = 1; i < list.size()-1; i++) {
+                temp_string += list.get(i).toString() + ", ";
+            }
+            temp_string += list.get(list.size()-1).toString();
+        }
+        return temp_string;
     }
 
     public Integer mostCommon() {
-        return null;
+        int most = 1;
+        //Most common value, start with array[0];
+        int val = list.get(0);
+        int current = 1;
+
+        for (int i = 1; i < list.size(); i++) {
+            if (list.get(i) == list.get(i-1)){
+                current++;
+            }else {
+                if (current > most) {
+                    most = current;
+                    val = list.get(i-1);
+                }
+                current = 1;
+            }
+        }
+        // If last element is most frequent
+        if (current > most) {
+            most = current;
+            val = list.get(list.size()-1);
+        }
+        return val;
     }
 
     public Boolean contains(Integer valueToAdd) {
-        return null;
+        return list.contains(valueToAdd);
     }
 
 }

src/main/java/com/dtcc/exams/part2/Router.java

@@ -1,22 +1,39 @@
 package com.dtcc.exams.part2;
 
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
 public class Router {
+    //<PATH, CONTROLLER>
+    Map<String,String> routerMap = new LinkedHashMap<>();
 
-    public void add(String path, String controller) {
-    }
+    public void add(String path, String controller) {routerMap.put(path, controller);}
 
-    public Integer size() {
-        return null;
-    }
+    public Integer size() {return routerMap.size();}
 
     public String getController(String path) {
-        return null;
+        return routerMap.get(path);
     }
 
     public void update(String path, String studentController) {
+        routerMap.remove(path);
+        routerMap.put(path, studentController);
     }
 
-    public void remove(String path) {
+    public void remove(String path) {routerMap.remove(path);
+    }
+
+    public String toString(){
+        String temp_string="";
+
+        //Entries, each entry
+        for(Map.Entry m:routerMap.entrySet()){
+            String key = (String)m.getKey();
+            String value = (String)m.getValue();
+            temp_string += (key + " -> " + value + "\n");
+        }
+        return temp_string;
     }
 
 }

src/main/java/com/dtcc/exams/part3/Bird.java

@@ -1,14 +1,15 @@
 package com.dtcc.exams.part3;
 
-public class Bird {
+public abstract class Bird {
+
+    private int speed;
+    private String move;
 
     public String move() {
-        return null;
+        return "fly";
     }
 
-    public void setMigrationMonth(String expected) {
-
-    }
+    public void setMigrationMonth(String expected) {}
 
     public String getMigrationMonth() {
         return null;

src/main/java/com/dtcc/exams/part3/Horse.java

@@ -1,4 +1,17 @@
 package com.dtcc.exams.part3;
 
-public class Horse {
+public class Horse implements Animal{
+
+    @Override
+    public String move() {return "gallop";}
+
+    @Override
+    public int getSpeed() {
+        return 40;
+    }
+
+    @Override
+    public String color() {
+        return "black";
+    }
 }

src/main/java/com/dtcc/exams/part3/PeregrineFalcon.java

@@ -1,4 +1,14 @@
 package com.dtcc.exams.part3;
 
-public class PeregrineFalcon {
+public class PeregrineFalcon extends Bird implements Animal {
+
+    @Override
+    public int getSpeed() {
+        return 13;
+    }
+
+    @Override
+    public String color() {
+        return "brown";
+    }
 }

src/main/java/com/dtcc/exams/part3/RedRobin.java

@@ -1,4 +1,23 @@
 package com.dtcc.exams.part3;
 
-public class RedRobin {
+public class RedRobin extends Bird implements Animal {
+
+    private String migrationMonth;
+
+    @Override
+    public int getSpeed() {
+        return 10;
+    }
+
+    @Override
+    public String color() {
+        return "red";
+    }
+
+    public void setMigrationMonth(String month){
+        this.migrationMonth = month;
+    }
+    public String getMigrationMonth() {
+        return this.migrationMonth;
+    }
 }

src/main/java/com/dtcc/exams/part3/SpeedComparator.java

@@ -1,4 +1,9 @@
 package com.dtcc.exams.part3;
 
-public class SpeedComparator {
+import java.util.Comparator;
+
+public class SpeedComparator implements Comparator<Animal> {
+
+    public int compare(Animal animal1, Animal animal2){return (animal2.getSpeed()-animal1.getSpeed());
+    }
 }

src/test/java/com/dtcc/exams/TestUtils.java

@@ -9,7 +9,6 @@ public class TestUtils {
     public static void assertArrayEquals(Object[] expected, Object[] actual) {
         Arrays.sort(actual);
         Arrays.sort(expected);
-
         // then
         Assert.assertEquals(Arrays.toString(expected), Arrays.toString(actual));
     }

src/test/java/com/dtcc/exams/part1/basicutilities/StartsWithTest.java

@@ -17,6 +17,7 @@ public void test2() {
 
     @Test
     public void test3() {
+
         test("jump", 'z', false);
     }