Find a triplet from three linked lists with a sum equal to a given number in C++

In this tutorial, we are going to write a program that finds the triplet in the linked list whose sum is equal to the given number.

Let's see the steps to solve the problem.

• Create a struct node for the linked list.

• Create the linked list with dummy data.

• Write three inner loops for three elements which iterate until the end of the linked list.

  • Add the three elements.

  • Compare the sum with the given number.

  • If both are equal, then print the elements and break the loops.

Example

Let's see the code.

 Live Demo

#include <bits/stdc++.h> using namespace std; class Node {    public:    int data;    Node* next; }; void insertNewNode(Node** head_ref, int new_data) {    Node* new_node = new Node();    new_node->data = new_data;    new_node->next = (*head_ref);    *head_ref = new_node; } void findTriplet(Node *head_one, Node *head_two, Node *head_three, int givenNumber) {    bool is_triplet_found = false;    Node *a = head_one;    while (a != NULL) {       Node *b = head_two;       while (b != NULL) {          Node *c = head_three;          while (c != NULL) {             int sum = a->data + b->data + c->data;             if (sum == givenNumber) {                cout << a->data << " " << b->data << " " << c->data << endl;                is_triplet_found = true;                break;             }             c = c->next;          }          if (is_triplet_found) {             break;          }          b = b->next;       }       if (is_triplet_found) {          break;       }       a = a->next;    }    if (!is_triplet_found) {       cout << "No triplet found" << endl;    } } int main() {    Node* head_one = NULL;    Node* head_two = NULL;    Node* head_three = NULL;    insertNewNode (&head_one, 4);    insertNewNode (&head_one, 3);    insertNewNode (&head_one, 2);    insertNewNode (&head_one, 1);    insertNewNode (&head_two, 4);    insertNewNode (&head_two, 3);    insertNewNode (&head_two, 2);    insertNewNode (&head_two, 1);    insertNewNode (&head_three, 1);    insertNewNode (&head_three, 2);    insertNewNode (&head_three, 3);    insertNewNode (&head_three, 4);    findTriplet(head_one, head_two, head_three, 9);    findTriplet(head_one, head_two, head_three, 100);    return 0; }

Output

If you run the above code, then you will get the following result.

1 4 4 No triplet found

Conclusion

If you have any queries in the tutorial, mention them in the comment section.