Doubly Linked List – Implementation in C/C++

what is head at 7:13 ? Is it of type struct node ?

sir i implement function for the insertion at nth position,in forward function it print but in the case of reverse print it doesn't print the element of nth insertion
InsertAtN(int x,int n)

{

Node* temp = GetNewNode(x);

Node*temp1 = head;

for(int i = 0; i<n-2; i++)

{

temp1 = temp1->next;

}

temp->next = temp1->next;

temp->prev = temp1;

temp1->next = temp;

Node* temp2 = temp->next;

temp2->prev = temp1;

}

Can we used Node *head without struct

Hi i want to create a singly linked list in C with 4 nodes. The first two nodes should contain strings and the last 2 nodes should contain numbers (int). I know how to create a linked list with integers as data types, but I don't know how to input strings into the nodes. Can you help me?

thanks sir clearing some concptes.. where is code?

thanks animesh

AAP BHAGWAN HO!

You can use typedef struct
And then you can (node*) instead of (struct node*)

Thanks, I appreciated this a lot.

Yaar bhai tum saviour ho,I can not thank you enough .Seriously.

When the new node was created with the address 600 was it suppose to be | 0 | 4 | 0| ?

please do a video for deletion with the same format of the code

hello thank you foe the video its awesome!
i have a question and its killing me, at 8:32 you're inserting InsertAtHead(2) and InsertAtHead(4) but in your drawing you have '2' in address 400 and '2' in address in 600 did you mean to put 4 ?? or are we replicating the Head with the val 2?

reverse a doubly linked list(Not printing) this problem has cost me my fucking interview

please do make more videos on linked list various operations like swapping alternate nodes..!!!

BEST Tutorials of DS…excellent explanation…supreme clarity and knowledge

9:47

wait , so by the way you insert node, after the second and third insertions,
the order will actually be " head (which is the third insert node) -> node (from the second insertion) -> node( from the first insertion) "
Therefore, you are always making the new insert node as the first one in the list but not the last one ?

Can anyone tell me what is the standard way or most common way to order the double link list when it comes to insertion ?

nice explanation

thanks a lot #humblefool

I did all main functions with proper *head arg in C++.
Couldn't have done it without this great teacher! Thank you very much!

#include <iostream>

#include <new>

struct Node {

int data;

Node* prev;

Node* next;

};

Node* GetNewNode(int data) {

Node* newNode = new Node();

newNode->data = data;

newNode->prev = NULL;

newNode->next = NULL;

return newNode;

}

Node* InsertStart(Node* headP, int data) {

Node* newNode = GetNewNode(data);

if (headP == NULL) {

headP = newNode;

} else {

headP->prev = newNode;

newNode->next = headP;

headP = newNode;

}

return headP;

}

Node* InsertEnd(Node* headP, int data) {

Node* newNode = GetNewNode(data);

if (headP == NULL) {

headP = newNode;

} else {

Node* prevNode = headP;

while (prevNode->next != NULL) {

prevNode = prevNode->next;

}

prevNode->next = newNode;

newNode->prev = prevNode;

}

return headP;

}

Node* InsertPos(Node* headP, int data, int pos) {

Node* newNode = GetNewNode(data);

if (pos == 1) {

headP->prev = newNode;

newNode->next = headP;

headP = newNode;

} else {

Node* prevNode = headP;

for (int i = 1; i < pos-1; i++) {

prevNode = prevNode->next;

}

newNode->next = prevNode->next;

newNode->prev = prevNode;

if (prevNode->next != NULL) prevNode->next->prev = newNode;

prevNode->next = newNode;

}

return headP;

}

Node* Delete(Node* headP, int pos) {

Node* temp = headP;

if (pos == 1) {

temp->next->prev = NULL;

headP = temp->next;

delete temp;

} else {

for (int i = 1; i < pos-1; i++) {

temp = temp->next;

}

Node* currentPos = temp->next;

temp->next = currentPos->next;

if (currentPos->next != NULL) currentPos->next->prev = temp;

delete currentPos;

}

return headP;

}

Node* Reverse(Node* headP) {

while (headP->next != NULL) {

headP = headP->next;

headP->prev->next = headP->prev->prev;

headP->prev->prev = headP;

}

headP->next = headP->prev;

headP->prev = NULL;

return headP;

}

void Print(Node* headP) {

std::cout << "Forward:";

while (headP != NULL) {

std::cout << " " << headP->data;

headP = headP->next;

}

std::cout << std::endl;

}

void ReversePrint(Node* headP) {

if (headP == NULL) return;

while (headP->next != NULL) {

headP = headP->next;

}

std::cout << "Reverse:";

while (headP != NULL) {

std::cout << " " << headP->data;

headP = headP->prev;

}

std::cout << std::endl;

}

int main() {

Node* listNumbers = NULL;

listNumbers = InsertStart(listNumbers, 2);

listNumbers = InsertStart(listNumbers, 4);

listNumbers = InsertStart(listNumbers, 8);

listNumbers = InsertStart(listNumbers, 1);

Print(listNumbers);

ReversePrint(listNumbers);

listNumbers = InsertEnd(listNumbers, 6);

listNumbers = InsertEnd(listNumbers, 0);

listNumbers = InsertEnd(listNumbers, 7);

listNumbers = InsertEnd(listNumbers, 5);

Print(listNumbers);

ReversePrint(listNumbers);

listNumbers = Delete(listNumbers, 3);

listNumbers = Delete(listNumbers, 5);

Print(listNumbers);

ReversePrint(listNumbers);

listNumbers = Reverse(listNumbers);

Print(listNumbers);

ReversePrint(listNumbers);

listNumbers = InsertPos(listNumbers, 3, 2);

listNumbers = InsertPos(listNumbers, 9, 8);

Print(listNumbers);

ReversePrint(listNumbers);

return 0;

}

JAVA CODE – REVERSE PRINT

public void showReverse() {
Node pointer = head;
while (pointer.getNext()!=null) {
pointer=pointer.getNext();
}

while(pointer!=null) {
System.out.print(pointer.getValue()+"|");
pointer=pointer.getPrev();
}
System.out.println();
}

JAVA CODE – PRINT

public void show() {
Node pointer = head;
while(pointer!=null) {
System.out.print(pointer.getValue()+ "|");
pointer= pointer.getNext();
}
System.out.println();
}

JAVA CODE – INSERT

public boolean insertItem(int item) {

System.out.println("Inserting item: "+ item);
Node newNode = new Node(item);

if(head==null) {
head = newNode;
head.setPrev(null);
head.setNext(null);
return true;
}

/**Inserting element at the head**/
/*newNode.setNext(head);
head.setPrev(newNode);
newNode.setPrev(null);
head=newNode;*/

/**Inserting element at the tail**/
Node pointer = head;
while(pointer.getNext()!=null) {
pointer = pointer.getNext();
}
pointer.setNext(newNode);
newNode.setPrev(pointer);
newNode.setNext(null);

return true;
}

Please upload video of circular linked list

thank you for your video sir!!!!!!

how to insert a node inbetween?

RIP man, even though you are no more your videos are still helping us all.

hmmmmm

Allocated memory is never free'd in your code = memory leak

wow sir
finally i understand why we are using dynamic memory allocation instead of normal allocation
i know you cant read any of our comments but still i want to say that u will always be the best teacher not only for me but for most of the online community who are still watching and learning from your videos