diff --git a/Cars.java b/Cars.java
new file mode 100644
index 0000000..01276fa
--- /dev/null
+++ b/Cars.java
@@ -0,0 +1,24 @@
+import java.util.*;
+
+public class Cars {
+    public static void main(String[] args){
+        Queue<String> cars = new LinkedList<>();
+        Scanner scn = new Scanner(System.in);
+
+        int n = scn.nextInt();
+        for (int i = 0; i < n; i++) {
+            cars.add(scn.next());
+        }
+
+        for (int i = 0; i < n; i++) {
+            System.out.println(cars.poll());
+        }
+
+        if (cars.isEmpty()){
+            System.out.println("is empty");
+        }
+        else {
+            System.out.println("is not empty");
+        }
+    }
+}
diff --git a/Detective.java b/Detective.java
index 5707416..9b166ff 100644
--- a/Detective.java
+++ b/Detective.java
@@ -1,8 +1,5 @@
- 
 import java.util.ArrayList;
-
 class ToDos {
-    
   public static void main(String[] args) {
     
     // Sherlock
@@ -26,10 +23,20 @@ public static void main(String[] args) {
     
     // Print the size of each ArrayList below:
 
-    
+    System.out.println("Sherlock: " + sherlocksToDos.size());
+    System.out.println("Poirot: " + poirotsToDos.size());
       
     // Print the name of the detective with the larger to-do list:
-    
+
+    String busyDetective;
+    if (sherlocksToDos.size() > poirotsToDos.size()){
+      busyDetective = "Sherlock";
+    }
+    else {
+      busyDetective = "Sherlock";
+    }
+    System.out.println(busyDetective);
+
   }
   
 }
diff --git a/HashCollisionChecker.java b/HashCollisionChecker.java
index 80631a7..75be41f 100644
--- a/HashCollisionChecker.java
+++ b/HashCollisionChecker.java
@@ -2,13 +2,19 @@
 
 public class HashCollisionChecker {
     public static <T> int countOfUniqueHashCodes(HashSet<T> set) {
-        // TODO: Implement
-        return 0;
+        HashSet<Integer> HashCodes = new HashSet<>();
+        for (T member : set) {
+            HashCodes.add(member.hashCode());
+        }
+        return HashCodes.size();
     }
 
     public static <K, V> int countOfUniqueHashCodes(HashMap<K, V> map) {
-        // TODO: Implement
-        return 0;
+        HashSet<Integer> HashCodes = new HashSet<>();
+        for (K key : map.keySet()){
+            HashCodes.add(key.hashCode());
+        }
+        return HashCodes.size();
     }
 
     public static void main(String[] args) {
diff --git a/shuffle.java b/shuffle.java
new file mode 100644
index 0000000..3380405
--- /dev/null
+++ b/shuffle.java
@@ -0,0 +1,13 @@
+import java.util.*;
+public class shuffle {
+    public static void main(String[] args){
+        LinkedList<Integer> myLL = new LinkedList<>();
+        Scanner scn = new Scanner(System.in);
+        int n = scn.nextInt();
+        for (int i = 0; i < n; i++){
+            myLL.add(scn.nextInt());
+        }
+        Collections.shuffle(myLL);
+    }
+
+}
diff --git a/uni.java b/uni.java
new file mode 100644
index 0000000..b239786
--- /dev/null
+++ b/uni.java
@@ -0,0 +1,42 @@
+import java.util.Scanner;
+import java.util.*;
+
+public class uni {
+    public static void main(String args[]){
+        Scanner scn = new Scanner(System.in);
+        int studentsCount = scn.nextInt();
+        TreeSet<student> studentsTreeSet = new TreeSet<>();
+
+        for (int i=0 ; i < studentsCount ; i++){
+            String name = scn.next();
+            int id = scn.nextInt();
+            double gpa = scn.nextDouble();
+            student student=new student(name, id , gpa);
+            studentsTreeSet.add(student);
+        }
+    }
+    public static student searchId(int Id, TreeSet<student> studentsTreeSet){
+        student st = new student("john", 00, 0.00);
+        for (student i : studentsTreeSet){
+            if (i.id == Id){
+                st = i;
+            }
+        }
+        return st;
+    }
+
+    public static void printInfo(student st){
+        System.out.println("name :" + st.name+ "Id : "+ st.id+"gpa :" + st.gpa);
+    }
+}
+
+class student {
+    String name;
+    int id;
+    double gpa;
+    public student(String name , int id , double gpa){
+        this.name=name;
+        this.id=id;
+        this.gpa = gpa;
+    }
+}