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Ikki bog’lamli ro’yxatda teskari oz’gartirish

Ikki bog’lamli ro'yxatni teskari yo’naltirish muhim operatsiya hisoblanadi. Bunda biz oddiygina barcha tugunlarning oldingi va keyingi ko'rsatkichlarini almashtiramiz, shuningdek, bosh va quyruq ko'rsatkichlarini almashtiramiz.
Quyida ikki bog’lamli ro’yxat berilgan:



Quyidagi C++ dasturi ikki bog’lamli ro’yxatda teskari o’zgartirishni namoyish etadi.

#include

using namespace std;

//node declaration for doubly linked list

struct Node {

   int data;

   struct Node *prev, *next;

};

  

Node* newNode(int val)

{

   Node* temp = new Node;

   temp->data = val;

   temp->prev = temp->next = nullptr;

   return temp;

}

void displayList(Node* head)

{

   while (head->next != nullptr) {

      cout << head->data << " <==> ";

      head = head->next;

      }

   cout << head->data << endl;

}

  

// Insert a new node at the head of the list

void insert(Node** head, int node_data)

{

   Node* temp = newNode(node_data);

   temp->next = *head;

   (*head)->prev = temp;

   (*head) = temp;

}

  

// reverse the doubly linked list

void reverseList(Node** head)

{

   Node* left = *head, * right = *head;

  

   // traverse entire list and set right next to right

   while (right->next != nullptr)

   right = right->next;

  

   //swap left and right data by moving them towards each other till they meet or cross

   while (left != right && left->prev != right) {

  

      // Swap left and right pointer data

      swap(left->data, right->data);

  

      // Advance left pointer

      left = left->next;

  

      // Advance right pointer

      right = right->prev;

   }

}

int main()

{

   Node* headNode = newNode(5);

   insert(&headNode, 4);

   insert(&headNode, 3);

   insert(&headNode, 2);

   insert(&headNode, 1);

   cout << "Original doubly linked list: " << endl;

   displayList(headNode);

   cout << "Reverse doubly linked list: " << endl;

   reverseList(&headNode);

   displayList(headNode);

  

   return 0;

}

Natija:

Ikki bog’lamli asl ro’yxat

1 <==> 2 <==> 3 <==> 4 <==> 5

Ikki bog’lamli ro’yxatni teskari yo’naltirish

5 <==> 4 <==> 3 <==> 2 <==>1

Bu yerda biz chap va o'ng ko'rsatkichlarni almashtiramiz va ular uchrashguncha yoki bir-birlarini kesib o'tguncha bir-biriga qarab harakatlantiramiz. Keyin birinchi va oxirgi tugunlar almashtiriladi.