LinkedList Updated

Linkedlist🤐/db_linked_list.cpp

@@ -0,0 +1,149 @@
+#include <iostream>
+#include <malloc.h>
+using namespace std;
+int count = 0;
+//Only Create functions are created, deletion will be added soon ...
+struct dblink
+{
+    int data;
+    struct dblink *next, *prev;
+} *node, *head, *last, *temp;
+
+void create_at_begin()
+{
+    node = (struct dblink *)malloc(sizeof(struct dblink));
+    cout << "Enter data : ";
+    cin >> node->data;
+    node->next = node->prev = NULL;
+    if (head == NULL)
+        head = last = node;
+    else
+    {
+        node->next = head;
+        head->prev = node;
+        head = node;
+    }
+}
+
+void create_at_last()
+{
+    node = (struct dblink *)malloc(sizeof(struct dblink));
+    cout << "Enter data : ";
+    cin >> node->data;
+    node->next = node->prev = NULL;
+    if (head == NULL)
+        head = last = node;
+    else
+    {
+        last->next = node;
+        node->prev = last;
+        last = node;
+    }
+}
+
+void counti()
+{
+    count = 0;
+    temp = head;
+    while (temp != NULL)
+    {
+        temp = temp->next;
+        count++;
+    }
+}
+
+void create_at_mid()
+{
+    counti();
+    int pos;
+    cout << "Enter position : ";
+    cin >> pos;
+    if (pos == 1)
+    {
+        create_at_begin();
+        return;
+    }
+    else if (pos == count - 1)
+    {
+        create_at_last();
+        return;
+    }
+    else if (pos > count && pos < 0)
+    {
+        cout << "Invalid position\n";
+        return;
+    }
+    else
+    {
+        node = (struct dblink *)malloc(sizeof(struct dblink));
+        cout << "Enter data : ";
+        cin >> node->data;
+        node->next = node->prev = NULL;
+        if (head == NULL)
+        {
+            head = last = node;
+        }
+        else
+        {
+            int p = 1;
+            temp = head;
+            while (p < pos)
+            {
+                p++;
+                temp = temp->next;
+            }
+            // node->next=temp->next;
+            // temp->next=node;
+            // node->prev=temp;
+            // temp->next->next->prev=node;
+            temp->next=node;
+            temp->next->prev=node;
+
+            node->next=temp->next->next;
+            node->prev=temp;
+        }
+    }
+}
+void display()
+{
+    temp = head;
+    cout << "From Head\n";
+    while (temp != NULL)
+    {
+        cout << "Data is " << temp->data << endl;
+        temp = temp->next;
+    }
+    cout << "From Last \n";
+    temp = last;
+    while (temp != NULL)
+    {
+        cout << "Data is " << temp->data << endl;
+        temp = temp->prev;
+    }
+}
+
+int main()
+{
+    int ch;
+    cout << "1.Begin\n2.Last\n3.Mid\n4.Display\nEnter choice : ";
+    cin >> ch;
+    switch (ch)
+    {
+    case 1:
+        create_at_begin();
+        main();
+        break;
+    case 2:
+        create_at_last();
+        main();
+        break;
+    case 3:
+        create_at_mid();
+        main();
+        break;
+    case 4:
+        display();
+        main();
+        break;
+    }
+}

Linkedlist🤐/singly_linked_list.cpp

@@ -0,0 +1,146 @@
+#include<iostream>
+#include<malloc.h>
+using namespace std;
+int count;
+int pos;
+//I am more comforbtable with struct but I am using Class for practice 
+class Node{
+    public:
+    int data;
+    Node *next;
+}*node,*last,*temp,*head,*previous;
+
+void create_at_begin()
+{
+    node = (Node *) malloc (sizeof(Node));
+    cout<<"Enter Data ";
+    cin >> node->data;
+    node->next = NULL;
+    if(head == NULL)
+        head=last=node;
+    else{
+        node->next = head;
+        head = node;
+    }
+}
+
+void create_at_end()
+{
+    node= (Node*) malloc (sizeof(Node));
+    cout<<"Enter Data at Last.";
+    cin>>node->data;
+    node->next=NULL;
+    if(head==NULL)
+        head=last=node;
+    else
+    {
+        last->next=node;
+        last=node;
+    } 
+}
+
+void counti(){
+    temp=head;
+    while(temp!=NULL){
+        count++;
+        temp=temp->next;
+    }
+}
+
+void create_at_mid(){
+    int pos;
+    cout << "Enter position to enter : ";
+    cin  >> pos;
+    node= (Node*) malloc (sizeof(Node));
+    cout<<"Enter Data at "<<pos<<" : ";
+    cin>>node->data;
+    node->next=NULL;
+    counti();
+    if(pos==1){
+        create_at_end();
+        return;
+    }
+    else if (pos==count){
+        create_at_begin();
+        return;
+    }
+    if (pos > count || pos < 1){
+        cout << "invalid Position\n";
+        return;
+    }
+    else{
+        temp = head;
+        for(int i = 1; i <= pos - 1; i++){
+            temp = temp->next;
+        }
+        node->next = temp->next;
+        temp->next = node;
+    }
+
+}
+
+void display()
+{
+    temp=head;
+    while(temp!=NULL)
+    {
+        cout << "Data = "<<temp->data<<endl;
+        temp=temp->next;
+    }
+}
+
+void delete_from_mid()
+{   int ch;
+    int prev;
+    cout<<"Enter which node you want to delete: ";
+    cin>>pos;
+            temp = head;
+            while(temp!=NULL)
+            prev++;    
+            if(prev = pos-1){
+                previous->next=temp->next;
+            }
+            delete temp;
+}   
+
+void delete_from_front()
+{
+    temp=head;
+    head = head->next;
+    delete temp;
+}
+
+int main()
+{
+    int ch;
+    while(1){
+        cout<<"1. Add at BEGIN."<<endl;
+        cout<<"2. Add At LAST."<<endl;
+        cout<<"3. Add At Middle"<<endl;
+        cout<<"4. Delete."<<endl;
+        cout<<"5. Display."<<endl;
+        cout<<"Enter choice: ";
+        cin>>ch;
+        switch (ch)
+        {
+            case 1:
+                create_at_begin();
+                break;
+            case 2:
+                create_at_end();
+                break;
+            case 3:
+                create_at_mid();
+                break;
+            case 4:
+                delete_from_mid();
+                break;
+            case 5:
+                display();
+                break;
+            default:
+             cout<<"Incorrect Answer"<<endl;
+             return 0;
+        }
+    }
+}