Lecture 175:- Sum of All Elements in a Linked List

 

To find the sum of all elements in a linked list, you need to traverse the list from the head node to the tail node and add up the data values of each node. You can do this either iteratively or recursively. Here's the C++ code to calculate the sum of all elements in a singly linked list using both approaches:

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#include <iostream> using namespace std; // Node structure for singly linked list struct Node {    int data;    Node* next; }; // Function to create a new node with the given data Node* createNode(int data) {    Node* newNode = new Node();    newNode->data = data;    newNode->next = nullptr;    return newNode; } // Function to insert a new node at the end of the linked list void insertEnd(Node*& head, int data) {    Node* newNode = createNode(data);    if (head == nullptr) {        head = newNode;        return;    }    Node* temp = head;    while (temp->next != nullptr) {        temp = temp->next;    }    temp->next = newNode; } // Iterative function to calculate the sum of all elements in the linked list int sumLinkedListIterative(Node* head) {    int sum = 0;    Node* current = head;    while (current != nullptr) {        sum += current->data;        current = current->next;    }    return sum; } // Recursive function to calculate the sum of all elements in the linked list int sumLinkedListRecursive(Node* current) {    if (current == nullptr) {        return 0;    }    return current->data + sumLinkedListRecursive(current->next); } // Function to free memory allocated for the linked list void deleteLinkedList(Node*& head) {    while (head != nullptr) {        Node* temp = head;        head = head->next;        delete temp;    } } int main() {    Node* head = nullptr;    // Inserting elements into the linked list    insertEnd(head, 1);    insertEnd(head, 2);    insertEnd(head, 3);    insertEnd(head, 4);    insertEnd(head, 5);    // Calculating the sum of all elements in the linked list using iterative approach    int sumIterative = sumLinkedListIterative(head);    cout << "Sum of elements (Iterative): " << sumIterative << endl;    // Calculating the sum of all elements in the linked list using recursive approach    int sumRecursive = sumLinkedListRecursive(head);    cout << "Sum of elements (Recursive): " << sumRecursive << endl;    // Free memory and delete the linked list    deleteLinkedList(head);    return 0; }

In this code, we define a Node structure to represent each element in the linked list. The createNode function is used to create a new node with the given data. The insertEnd function inserts a new node at the end of the linked list. The sumLinkedListIterative function iteratively calculates the sum of all elements in the linked list. The sumLinkedListRecursive function recursively calculates the sum of all elements in the linked list.

When you run this code, it will display the sum of all elements in the linked list using both iterative and recursive approaches. For the given linked list, the output will be:

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Sum of elements (Iterative): 15 Sum of elements (Recursive): 15