Doubly Linked List CPP

Data Structures/Doubly Linked List/DoublyLinkedList.cpp

@@ -0,0 +1,241 @@
+/*
+First add number of nodes you need and then,
+Insert Space Separated values when asked.
+*/
+
+#include <iostream>
+#include <cstdlib>
+
+using namespace std;
+
+struct Node {
+    Node *next;
+    int data;
+    Node *prev;
+};
+
+class LinkedList {
+private:
+    Node *start = NULL;
+public:
+    void insertBeg(int x);    // Insert a new node at the beginning
+    void insertEnd(int x);    // Insert a node at the end
+    void deleteBeg();        // Delete a node from the beginning
+    void deleteEnd();        // Delete a node from the end
+    void deleteNode(int D); // Delete a node with a given value
+    void print();            // Print current list
+    Node *search(int F);    // Search an existing element
+    int sum();                // Add list values to get sum
+};
+
+//Insert New Node at the beginning
+void LinkedList::insertBeg(int x) {
+    Node *newNode = new Node;
+    //If there is no data in the link list
+    if (start == NULL) {
+        start = newNode;
+        newNode->data = x;
+        newNode->next = NULL;
+        newNode->prev = NULL;
+    } else {
+        newNode->prev = NULL;
+        newNode->data = x;
+        newNode->next = start;
+        start->prev = newNode;
+        start = newNode;
+    }
+    cout << "Element Inserted to End" << endl;
+}
+
+void LinkedList::insertEnd(int x) {
+    Node *newNode = new Node;
+    //If there is no data in the link list
+    if (start == NULL) {
+        newNode->data = x;
+        newNode->next = NULL;
+        newNode->prev = NULL;
+        start = newNode;
+    } else {
+        newNode->data = x;
+        newNode->next = NULL;
+        Node *ptr = start;
+
+        while (ptr->next != NULL) {    // Search for the last node
+            ptr = ptr->next;
+        }
+        ptr->next = newNode;
+        newNode->prev = ptr;
+        cout << "Node Inserted at the End";
+    }
+}
+
+void LinkedList::deleteBeg() {
+    //If there is no data in the link list
+    if (start == NULL) {
+        cout << "Link list is empty";
+        return;
+    }
+    Node *ptr = start;
+    start = start->next;
+    free(ptr);
+    cout << "Node delete from the beginning.";
+}
+
+void LinkedList::deleteEnd() {
+    //If there is no data in the link list
+    if (start == NULL) {
+        cout << "Linked list is empty" << endl;
+        return;
+    }
+    Node *ptr = start;
+    while (ptr->next != NULL) {    // Search for the last node
+        ptr = ptr->next;
+    }
+
+    ptr->prev->next = NULL;
+    free(ptr);
+}
+
+void LinkedList::deleteNode(int D) {
+    Node *ptr = start;
+
+    //If beginning value = D delete from beginning
+    if (start->data == D) {
+        deleteBeg();
+    } else {
+        while (ptr->next->next != NULL) {
+            ptr = ptr->next;
+            if (ptr->data == D) {
+                ptr->prev->next = ptr->next;
+                ptr->next->prev = ptr->prev;
+                free(ptr);
+                cout << "Node with value " << D << " Deleted.";
+                return;
+            }
+        }
+    }
+    //If end value = D delete from end
+    if (ptr->next->data == D) {
+        deleteEnd();
+    }
+}
+
+void LinkedList::print() {
+    Node *ptr = start;
+    //If there is no data in the link list
+    if (start == NULL) {
+        cout << "No data available " << endl;
+        return;
+    } else {
+        while (ptr != NULL) {    //count the number of nodes
+            cout << ptr->data << " ";
+            ptr = ptr->next;
+        }
+    }
+}
+
+Node *LinkedList::search(int F) {
+    Node *ptr = start;
+    while (ptr->next != NULL) {    // search for the element node by node
+        if (ptr->data == F) {
+            return ptr;
+        }
+        ptr = ptr->next;
+    }
+    return NULL;
+}
+
+int LinkedList::sum() {
+    int sum = 0;
+    Node *ptr = start;
+    while (ptr != NULL) {    // add data node by node
+        sum += ptr->data;
+        ptr = ptr->next;
+    }
+    return sum;
+}
+
+
+int main() {
+    LinkedList linkedList;
+    int num_nodes, values, input;
+
+    //Get number of initial nodes
+    cout << "Number of nodes : ";
+    cin >> num_nodes;
+
+    //Initializing the linklist
+    for (int i = 0; i < num_nodes; i++) {
+        cout << "Input data : ";    //get values
+        cin >> values;
+        linkedList.insertBeg(values);
+    }
+
+    cout << endl << endl;
+
+    while (true) {
+        cout << "1 - Insert Beginning\n"
+                "2 - Insert End\n"
+                "3 - Delete Beginning\n"
+                "4 - Delete End\n"
+                "5 - Delete Value\n"
+                "6 - Print\n"
+                "7 - Search\n"
+                "8 - Sum\n"
+                "0 - Exit\n\n";
+        cout << "Enter your choice : ";
+        cin >> input;
+        cout << endl;
+        switch (input) {
+            case 1:
+                cout << "Enter the value : ";
+                cin >> values;
+                linkedList.insertBeg(values);
+                break;
+            case 2:
+                cout << "Enter the value : ";
+                cin >> values;
+                linkedList.insertEnd(values);
+                break;
+            case 3:
+                linkedList.deleteBeg();
+                break;
+            case 4:
+                linkedList.deleteEnd();
+                break;
+            case 5:
+                cout << "\nEnter the value of the node to be delete : ";
+                cin >> values;
+                linkedList.deleteNode(values);
+                break;
+            case 6:
+                cout << "Link list : ";
+                linkedList.print();
+                break;
+            case 7:
+                cout << "Enter value to be searched : ";
+                cin >> values;
+                // Search an existing element
+                if (linkedList.search(values) != NULL)
+                    cout << "\nElement Found " << endl;
+                else
+                    cout << "\nElement Not Found" << endl;
+                break;
+            case 8:
+                cout << "The sum of the link list : ";
+                cout << linkedList.sum();
+                break;
+            case 0:
+                return 0;
+            default:
+                cout << "Invalid Input.";
+        }
+        cout << endl << endl;
+        cout << "Current link list : \t\n";
+        linkedList.print();
+        cout << endl << endl;
+        system("pause");
+        cout << endl << endl;
+    }
+    return 0;
+}