Doubly Linked List programs

Double Linkedlist/Header.h

@@ -0,0 +1,245 @@
+#ifndef LINKEDLIST_H
+#define LINKEDLIST_H
+
+#include <iostream>;
+#include "Stack.h";
+using namespace std;
+class linkedlist
+{
+
+
+public:
+	struct Node
+	{
+		Node *next = NULL;
+		Node *prev = NULL;
+		double val ;
+
+	};
+	Node *head=NULL;
+	Node * trav = NULL;
+	Node * temp = NULL;
+
+
+
+
+	void insert(double key) {
+
+		Node *newNode = new Node();
+		newNode->val = key;
+		newNode->next = NULL;
+
+		Node *forw = NULL;
+		Node *back = NULL;
+
+		if (head == NULL)
+		{
+			head = newNode;
+
+		}
+		else
+		{
+			forw = head;
+			while (forw)
+			{
+				back = forw;
+				forw = forw->next;
+			}
+			back->next = newNode;
+		}
+	}
+
+	void removeDuplicate() {
+
+		Node *prev = head;
+		Node *temp = NULL;
+
+
+				while (prev->next!=NULL)
+				{
+
+					if (prev->val==prev->next->val)
+					{
+						temp = prev->next;
+						prev->next = temp->next;
+						delete temp;
+					}
+					else
+					{
+						prev = prev->next;
+
+					}
+
+
+				}
+
+
+	}
+
+	/*void insert(double key) {
+
+		Node *newNode = new Node();
+		newNode->val = key;
+		newNode->next = NULL;
+
+		Node *forw = NULL;
+		Node *back = NULL;
+
+		if (head==NULL)
+		{
+			head = newNode;
+
+		}
+		else
+		{
+			forw = head;
+
+			while (forw!=NULL&&forw->val < key)
+			{
+				back = forw;
+				forw = forw->next;
+			}
+
+			if (back==NULL)
+			{
+				head = newNode;
+				newNode->next = forw;
+				forw->prev = newNode;
+			}
+			else if (forw!= NULL)
+			{
+				back->next = newNode;
+				newNode->next = forw;
+				forw->prev = newNode;
+			}
+			else
+			{
+				back->next = newNode;
+
+			}
+
+
+		}
+
+
+	}*/
+
+
+	void display() {
+
+		Node *trav = head;
+		while (trav != NULL)
+		{
+			std::cout << trav->val << ">>";
+			trav = trav->next;
+		}
+
+
+	}
+	void deletenode(double key) {
+
+		Node * frwd=head;
+		Node * prev = NULL;
+		Node * store = NULL;
+
+
+		while (frwd->val!=key &&frwd!= NULL)
+		{
+			prev = frwd;
+			frwd = frwd->next;
+		}
+
+		if (frwd->val==head->val)
+		{
+			store = head;
+			head = frwd->next;
+			delete store;
+		}
+		else if (frwd->next!= NULL)
+		{
+			store = frwd;
+			frwd = frwd->next;
+			prev->next = frwd;
+			frwd->prev = prev;
+			delete store;
+		}
+		else
+		{
+			prev->next = NULL;
+		}
+
+
+	}
+	Node* detectloop(Node *head) {
+
+		Node *p = head;
+		Node *q = head;
+
+		while (p&&q&&q->next)
+		{
+			p = p->next;
+			q = q->next->next;
+			if (p==q)
+			{
+				cout << "loop Detected";
+				return p;
+			}
+		}
+		cout << "No loop Detected";
+
+		return NULL;
+	}
+
+
+	void middleNode(Node *head) {
+
+		Node *slow = head;
+		Node *fast = head;
+
+		while (fast!=NULL&& fast->next!=NULL)
+		{
+
+				fast = fast->next->next;
+					slow = slow->next;
+
+
+		}
+
+		cout << "Middle Node is :" << slow->val;
+	}
+
+	void removeLoop(Node *p, Node *head) {
+
+		Node *q = head;
+
+		while (p->next!=q->next)
+		{
+			p = p->next;
+			q = q->next;
+		}
+
+		p->next = NULL;
+
+	}
+
+
+	void reverseLL(Node *head) {
+
+
+		Node *tmp = NULL;
+		Node *ptr = head;
+		while (ptr->val != 10) {
+			tmp = ptr->next;
+			ptr->next = ptr->prev;
+			ptr->prev = tmp;
+			if (tmp==NULL) {
+				head = ptr;
+				break;
+			}
+
+			ptr = tmp;
+		}
+		display();
+	}
+};
+#endif

Double Linkedlist/New Text Document.txt

@@ -0,0 +1,9 @@
+This program contain all double linked ist problems listed below...
+
+.) Delete node from start, End or middle
+.) Check loop in a linked list, looped index nad removal of loop
+.) Add a node
+.) inorder, preorder,postorder
+.) Finding middle node
+.) finding given node
+.) No of occurance of a value

Double Linkedlist/Stack.h

@@ -0,0 +1,91 @@
+
+#ifndef INTSTACK_H
+ #define INTSTACK_H
+#include <iostream>;
+using namespace std;
+
+ class IntStack
+ {
+ private:
+	 int *stackArray; // Pointer to the stack array
+	 int stackSize; // The stack size
+	  // Indicates the top of the stack
+
+ public:
+	 int top;
+	 // Constructor
+		 IntStack(int size =10)
+		 {
+			  stackArray = new int[7];
+			  stackSize = size;
+			  top = -1;
+
+		 }
+
+
+
+
+		 // Destructor
+		 ~IntStack()
+		 {
+			  delete[] stackArray;
+
+		 }
+
+		 // Stack operations
+		 void push(int num)
+		 {
+			  if (isFull())
+				  {
+				  cout << "The stack is full.\n";
+				  }
+			  else
+				  {
+				  top++;
+				  stackArray[top] = num;
+				  }
+
+		 }
+	 int pop()
+
+	 {
+		 int num;
+		  if (isEmpty())
+			  {
+			 cout << "The stack is empty.\n";
+			  }
+		 else
+			  {
+			  num = stackArray[top];
+			  top--;
+			  }
+		  return num;
+
+	 }
+
+	 bool isFull() const
+	 {
+		  bool status;
+
+			  if (top == stackSize -1)
+			  status = true;
+		  else
+			  status = false;
+
+			  return status;
+
+	 }
+	 bool isEmpty() const
+	 {
+		  bool status;
+
+			  if (top == -1)
+			  status = true;
+		  else
+		  status = false;
+
+			  return status;
+		  }
+	 };
+ #endif
+