diff --git a/notes/Unit 3/quicksort.ppt b/notes/Unit 3/quicksort.ppt
new file mode 100644
index 0000000..ac1e242
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diff --git a/notes/Unit 6/Dqueue.cpp b/notes/Unit 6/Dqueue.cpp
new file mode 100644
index 0000000..cca3203
--- /dev/null
+++ b/notes/Unit 6/Dqueue.cpp	
@@ -0,0 +1,133 @@
+#include<iostream>
+using namespace std;
+#define SIZE 20
+class dequeue 
+{
+   int a[20],f,r;
+   public:
+      dequeue();
+      void insert_at_beg(int);
+      void insert_at_end(int);
+      void delete_fr_front();
+      void delete_fr_rear();
+      void show();
+};
+
+dequeue::dequeue() 
+{
+   f=-1;
+   r=-1;
+}
+
+void dequeue::insert_at_end(int i)
+ {
+   if(r>=SIZE-1) 
+      cout<<"insertion is not possible, overflow!!!!";
+    else
+    {
+      if(f==-1)
+      {
+         f++;
+         r++;
+      } 
+      else 
+         r=r+1;
+      a[r]=i;
+      cout<<"Inserted item is"<<a[r];
+   }
+}
+
+void dequeue::insert_at_beg(int i) {
+   if(f==-1) {
+      f=0;
+      a[++r]=i;
+      cout<<" inserted element is:"<<i;
+   } 
+    else if(f!=0)
+    {
+      a[--f]=i;
+      cout<<" inserted element is:"<<i;
+   } 
+   else {
+      cout<<" insertion is not possible, overflow!!!";
+   }
+}
+void dequeue::delete_fr_front() {
+   if(f==-1) {
+      cout<<"deletion is not possible::dequeue is empty";
+      return;
+   }
+   else {
+      cout<<"the deleted element is:"<<a[f];
+      if(f==r) {
+         f=r=-1;
+         return;
+      } else
+         f=f+1;
+      }
+   }
+   void dequeue::delete_fr_rear() {
+      if(f==-1) {
+         cout<<"deletion is not possible::dequeue is empty";
+         return;
+      }
+      else {
+         cout<<"the deleted element is:"<<a[r];
+         if(f==r) {
+            f=r=-1;
+         } else
+            r=r-1;
+      }
+   }
+   void dequeue::show() {
+      if(f==-1) {
+         cout<<"Dequeue is empty";
+      } else {
+         for(int i=f;i<=r;i++) {
+            cout<<a[i]<<" ";
+         }
+      }
+   }
+
+int main() 
+{
+      int c,i;
+      dequeue d;
+      do//perform switch opeartion 
+      {
+      cout<<" 1.insert at beginning";
+      cout<<" 2.insert at end";
+      cout<<" 3.show";
+      cout<<" 4.deletion from front";
+      cout<<" 5.deletion from rear";
+      cout<<" 6.exit";
+      cout<<" enter your choice:";
+      cin>>c;
+      switch(c)
+	 {
+         case 1:
+            cout<<"enter the element to be inserted";
+            cin>>i;
+            d.insert_at_beg(i);
+         break;
+         case 2:
+            cout<<"enter the element to be inserted";
+            cin>>i;
+            d.insert_at_end(i);
+         break;
+         case 3:
+            d.show();
+            break;
+         case 4:
+            d.delete_fr_front();
+            break;
+         case 5:
+            d.delete_fr_rear();
+            break;
+         default:
+            cout<<"invalid choice";
+            break;
+      }
+   }while(c!=7);
+return 0;
+}
diff --git a/notes/Unit 6/UNIT VI Queue.pptx b/notes/Unit 6/UNIT VI Queue.pptx
new file mode 100644
index 0000000..5718cf4
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diff --git a/notes/Unit 6/priorityQueue.cpp b/notes/Unit 6/priorityQueue.cpp
new file mode 100644
index 0000000..a15547b
--- /dev/null
+++ b/notes/Unit 6/priorityQueue.cpp	
@@ -0,0 +1,158 @@
+#include<iostream>
+#include<string>
+
+#define N 20
+
+#define SERIOUS 10
+#define NONSERIOUS 5
+#define CHECKUP 1
+
+using namespace std;
+string Q[N];
+int Pr[N];
+int r = -1,f = -1;
+void enqueue(string data,int p)//Enqueue function to insert data and its priority in queue
+{
+	int i;
+	if((f==0)&&(r==N-1)) //Check if Queue is full
+		cout<<"Queue is full";
+	else 
+	{
+		if(f==-1) 
+		{ //if Queue is empty
+			f = r = 0;
+			Q[r] = data;
+			Pr[r] = p;
+
+		}
+		else if(r == N-1) 
+		{ //if there there is some elemets in Queue
+			for(i=f;i<=r;i++) 
+			{ 
+                    Q[i-f] = Q[i]; 
+                    Pr[i-f] = Pr[i];
+                    r = r-f; 
+                    f = 0;
+                    for(i = r;i>f;i--) 
+                    {
+				        if(p>Pr[i]) 
+				        {
+					        Q[i+1] = Q[i];
+					        Pr[i+1] = Pr[i];
+				        }
+				        else break;
+					
+				        Q[i+1] = data;
+				        Pr[i+1] = p;
+				        r++;
+				    }
+			}
+		}
+		
+		else 
+		{
+			for(i = r;i>=f;i--) 
+			{
+				if(p>Pr[i]) 
+				{
+					Q[i+1] = Q[i];
+					Pr[i+1] = Pr[i];	
+				}
+				else break;
+			}
+			Q[i+1] = data;
+			Pr[i+1] = p;
+			r++;
+		}	
+	}
+
+}
+void print() { //print the data of Queue
+	int i;
+	for(i=f;i<=r;i++) {
+		cout << "Patient's Name - "<<Q[i];
+		switch(Pr[i]) {
+			case 1: 
+				cout << " Priority - 'Checkup' " << endl;
+			break;
+			case 5:
+				cout << " Priority - 'Non-serious' " << endl;
+			break;
+			case 10:
+				cout << " Priority - 'Serious' " << endl;
+			break;
+			default:
+				cout << "Priority not found" << endl;
+		}
+	}
+}
+
+void dequeue() { //remove the data from front
+	if(f == -1) 
+	{
+		cout<<"Queue is Empty";
+	}	
+	else 
+	{
+	    cout<<"deleted Element ="<<Q[f]<<endl;
+	    cout<<"Its Priority = "<<Pr[f]<<endl;
+		if(f==r) f = r = -1;
+		else f++;
+	}
+}
+
+int main() 
+{
+	string data;
+	int opt,n,i,p;
+	cout<<"Enter Your Choice:-"<<endl;
+	do {
+	cout << "\n 1 : Insert the Data in Queue" << endl << "2: Display the Queue " << endl << "3: Delete the data from the Queue" 
+		<< endl << "0 for Exit"<< endl;
+	cin >> opt;
+		switch(opt) {
+			case 1:
+				cout << "Enter the number of Patient" << endl;
+				cin >> n;
+				i = 0;
+				while(i < n) {
+					cout << "Enter your name of the patient : ";
+					cin >> data;
+					ifnotdoagain: 
+						cout << "Enter your Priority (0: serious, 1: non-serious, 2: general checkup) : ";
+						cin >> p;
+						switch(p) {
+							case 0: 
+								enqueue(data,SERIOUS);
+							break;
+							case 1: 
+								enqueue(data,NONSERIOUS);
+							break;
+							case 2: 
+								enqueue(data,CHECKUP);
+							break;
+							default:
+								goto ifnotdoagain;
+						}
+						
+					i++;
+				}
+			break;
+			case 2:
+				print();
+			break;
+			case 3:
+				 dequeue();
+			break;
+			case 0:
+				cout << "Bye Bye !" << endl;
+			break;
+			default:
+			cout<<"Incorrect Choice"<<endl;
+
+		}
+	}while(opt!=0);
+        return 0;
+}
+
+