Answer to Question #251044 in C++ for SCADA HDMI

Question

Write a function to randomly delete a node in a doubly circular link list. The return type of this function

is void, and it will not accept any parameter. Then write a main() program to test your code. Here is

the sample output of the program.

Initial doubly link list is:

40 50 10 30 65 18 72

The computer has randomly chosen node number 5 to delete

The link list after deletion of node is

40 50 10 30 18 72

Answer 1

#include <iostream>
#include <stdlib.h>
#include <time.h>
using namespace std;
class Node{
    public:
    int data;
    Node *next, *prev;
    Node();
    Node(int);
};
Node::Node(){
    next = NULL;
    prev = NULL;
}
Node::Node(int data){
    this->data = data;
    next = NULL;
    prev = NULL;
}
class DoublyLinkedList{
    Node *head, *tail;
    int size;


    public:
    DoublyLinkedList();
    void insert(int);
    void remove(int);
    void show();
    int length(){return size;}
};
DoublyLinkedList::DoublyLinkedList(){
    head = NULL;
    tail = NULL;
    size = 0;
}
void DoublyLinkedList::insert(int data){
    if(head == NULL){
        head = new Node(data);
        tail = head;
        size++;
    }
    else{
        tail->next = new Node(data);
        tail->next->prev = tail;
        tail = tail->next;
        size++;
    }
}
void DoublyLinkedList::remove(int pos){
    if(head != NULL){
        int i = 0;
        Node *temp = head;
        while(temp != NULL && i < pos){
            temp = temp->next;
            i++;
        }
        if(pos > size - 1) return;
        if(pos == 0){
            head = head->next;
            head->prev = NULL;
            size--;
            delete temp;
            return;
        }
        if(pos == size - 1){
            tail = tail->prev;
            tail->next = NULL;
            size--;
            delete temp;
            return;
        }
        temp->prev->next = temp->next;
        temp->next->prev = temp->prev;
        size--;
        delete temp;
    }
}
void DoublyLinkedList::show(){
    Node* curr = head;
    while(curr != NULL){
        cout<<curr->data<<" ";
        curr = curr->next;
    }
    cout<<endl;
}


DoublyLinkedList list;
void removeRandom(){
    int size = list.length();
    int position = rand() % size;
    cout<<"The computer has randomly chosen node number "<<position + 1<<" to delete\n";
    list.remove(position);
}
int main(){
    srand(time(NULL));
    list.insert(40);
    list.insert(50);
    list.insert(10);
    list.insert(30);
    list.insert(65);
    list.insert(18);
    list.insert(72);
    cout<<"Initial doubly link list is: \n";
    list.show();
    removeRandom();
    cout<<"The link list after deletion of node is: \n";
    list.show();
    return 0;
}