Given a linked list, the task is to print the product of alternate nodes of the given linked list.
Examples:
Input : 1 -> 8 -> 3 -> 10 -> 17 -> 22 -> 29 -> 42 Output : 1479 Alternate nodes : 1 -> 3 -> 17 -> 29 Input : 10 -> 17 -> 33 -> 38 -> 73 Output : 24090 Alternate nodes : 10 -> 33 -> 73
Iterative Approach:
- Traverse the whole linked list.
- Set prod = 1 and count=0.
- Multiply the data of the node with the prod when the count is even.
- Visit the next node.
Below is the implementation of this approach:
C++
// C++ code to print the product of Alternate Nodes#include <bits/stdc++.h>using namespace std;/* Link list node */struct Node { int data; struct Node* next;};/* Function to get the product of alternatenodes of the linked list */int productAlternateNode(struct Node* head){ int count = 0; int prod = 1; while (head != NULL) { // when count is even product the data of node if (count % 2 == 0) prod *= head->data; // count the nodes count++; // move on the next node. head = head->next; } return prod;}// Function to push node at headvoid push(struct Node** head_ref, int new_data){ struct Node* new_node = new Node; new_node->data = new_data; new_node->next = (*head_ref); (*head_ref) = new_node;}// Driver codeint main(){ /* Start with the empty list */ struct Node* head = NULL; /* Use push() function to construct the below list 8 -> 23 -> 11 -> 29 -> 12 */ push(&head, 12); push(&head, 29); push(&head, 11); push(&head, 23); push(&head, 8); cout << productAlternateNode(head); return 0;}// This code is contributed by shivani singh |
C
// C code to print the product of Alternate Nodes#include <stdio.h>#include <stdlib.h>/* Link list node */struct Node { int data; struct Node* next;};/* Function to get the product of alternate nodes of the linked list */int productAlternateNode(struct Node* head){ int count = 0; int prod = 1; while (head != NULL) { // when count is even product the data of node if (count % 2 == 0) prod *= head->data; // count the nodes count++; // move on the next node. head = head->next; } return prod;}// Function to push node at headvoid push(struct Node** head_ref, int new_data){ struct Node* new_node = (struct Node*)malloc(sizeof(struct Node)); new_node->data = new_data; new_node->next = (*head_ref); (*head_ref) = new_node;}// Driver codeint main(){ /* Start with the empty list */ struct Node* head = NULL; /* Use push() function to construct the below list 8 -> 23 -> 11 -> 29 -> 12 */ push(&head, 12); push(&head, 29); push(&head, 11); push(&head, 23); push(&head, 8); printf(" %d ", productAlternateNode(head)); return 0;} |
Java
// Java code to print the product of Alternate Nodes class GFG{ /* Link list node */static class Node { int data; Node next; }; /* Function to get the alternate nodes of the linked list */static int productAlternateNode( Node head) { int count = 0; int product = 1; while (head != null) { // when count is even product the nodes if (count % 2 == 0) product *= head.data; // count the nodes count++; // move on the next node. head = head.next; } return product; } // Function to push node at head static Node push( 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; return head_ref;} // Driver code public static void main(String args[]){ /* Start with the empty list */ Node head = null; /* Use push() function to con the below list 8 . 23 . 11 . 29 . 12 */ head = push(head, 12); head = push(head, 29); head = push(head, 11); head = push(head, 23); head = push(head, 8); System.out.printf(" %d ", productAlternateNode(head)); } }// This code is contributed by Arnab Kundu |
Python3
# Python3 code to print the # product of Alternate Nodesimport math# Link list node class Node: def __init__(self, data): self.data = data self.next = None# Function to get the product of alternate# nodes of the linked list def productAlternateNode(head): count = 0 prod = 1 while (head != None): # when count is even, product # the data of node if (count % 2 == 0): prod *= head.data # count the nodes count = count + 1 # move on the next node. head = head.next return prod# Function to head=push node at headdef push(head_ref, new_data): new_node = Node(new_data) #new_node.data = new_data new_node.next = head_ref head_ref = new_node return head_ref# Driver codeif __name__=='__main__': # Start with the empty list head = None # Use head=push() function to construct #the below list 8 . 23 . 11 . 29 . 12 head = push(head, 12) head = push(head, 29) head = push(head, 11) head = push(head, 23) head = push(head, 8) print(productAlternateNode(head))# This code is contributed by Srathore |
C#
// C# code to print the product of Alternate Nodes using System;class GFG { /* Link list node */public class Node { public int data; public Node next; }; /* Function to get the alternate nodes of the linked list */static int productAlternateNode( Node head) { int count = 0; int product = 1; while (head != null) { // when count is even product the nodes if (count % 2 == 0) product *= head.data; // count the nodes count++; // move on the next node. head = head.next; } return product; } // Function to push node at head static Node push( 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; return head_ref; } // Driver code public static void Main(String []args) { /* Start with the empty list */ Node head = null; /* Use push() function to con the below list 8 . 23 . 11 . 29 . 12 */ head = push(head, 12); head = push(head, 29); head = push(head, 11); head = push(head, 23); head = push(head, 8); Console.Write(" {0} ", productAlternateNode(head)); } } // This code has been contributed by 29AjayKumar |
Javascript
<script> // javascript code to print the product of Alternate Nodes /* Link list node */ class Node { constructor(val) { this.data = val; this.next = null; } } /* * Function to get the alternate nodes of the linked list */ function productAlternateNode(head) { var count = 0; var product = 1; while (head != null) { // when count is even product the nodes if (count % 2 == 0) product *= head.data; // count the nodes count++; // move on the next node. head = head.next; } return product; } // Function to push node at head function push(head_ref , new_data) { var new_node = new Node(); new_node.data = new_data; new_node.next = (head_ref); (head_ref) = new_node; return head_ref; } // Driver code /* Start with the empty list */ var head = null; /* * Use push() function to construct the below list 8 . 23 . 11 . 29 . 12 */ head = push(head, 12); head = push(head, 29); head = push(head, 11); head = push(head, 23); head = push(head, 8); document.write( productAlternateNode(head));// This code contributed by Rajput-Ji</script> |
Output
1056
Complexity Analysis:
- Time Complexity: O(N)
- Auxiliary Space: O(1)
Recursive Approach:
- Initialize a static variable(say flag).
- If the flag is odd, multiply the node with the product.
- Increase head and flag by 1, and recurse for next nodes.
Below is the implementation of this approach:
C++
// CPP code to print alternate nodes// of a linked list using recursion#include <bits/stdc++.h>using namespace std;// A linked list nodestruct Node { int data; struct Node* next;};// Inserting node at the beginningvoid push(struct Node** head_ref, int new_data){ struct Node* new_node = new Node(); new_node->data = new_data; new_node->next = (*head_ref); (*head_ref) = new_node;}// Function to find product of alternate// nodes of linked list.// The boolean flag isOdd is used to find// if the current node is even or odd.void productAlternateNodes(struct Node* node, int& prod, bool isOdd = true){ if (node == NULL) return; if (isOdd == true) prod = prod * (node->data); productAlternateNodes(node->next, prod, !isOdd);}// Driver codeint main(){ // Start with the empty list struct Node* head = NULL; // construct below list // 8 -> 23 -> 11 -> 29 -> 12 push(&head, 12); push(&head, 29); push(&head, 11); push(&head, 23); push(&head, 8); int prod = 1; productAlternateNodes(head, prod); cout << prod; return 0;} |
Java
// Java code to print alternate nodes// of a linked list using recursionclass GFG{ // A linked list nodestatic class Node { int data; Node next;};// Inserting node at the beginningstatic Node push(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; return head_ref;}static int prod;// Function to find product of alternate// nodes of linked list.// The boolean flag isOdd is used to find// if the current node is even or odd.static void productAlternateNodes(Node node, boolean isOdd){ if (node == null) return; if (isOdd == true) prod = prod * (node.data); productAlternateNodes(node.next, !isOdd);}// Driver codepublic static void main(String args[]){ // Start with the empty list Node head = null; // construct below list // 8 . 23 . 11 . 29 . 12 head = push(head, 12); head = push(head, 29); head = push(head, 11); head = push(head, 23); head = push(head, 8); prod = 1; productAlternateNodes(head, true); System.out.println( prod);}}// This code is contributed by Arnab Kundu |
Python3
# Python3 code to print alternate nodes# of a linked list using recursion# Link list node class Node: def __init__(self, data): self.data = data self.next = next # function to insert a node at the# beginning of the linked listdef push(head_ref, new_data): # allocate node new_node = Node(0) # put in the data new_node.data = new_data # link the old list to the new node new_node.next = (head_ref) # move the head to point to the new node (head_ref) = new_node return head_refprod = 1# Function to find product of alternate# nodes of linked list.# The boolean flag isOdd is used to find# if the current node is even or odd.def productAlternateNodes(node, isOdd): global prod if (node == None): return if (isOdd == True): prod = prod * (node.data) productAlternateNodes(node.next, not isOdd)# Driver code# Start with the empty listhead = None# construct below list# 8 -> 23 -> 11 -> 29 -> 12head = push(head, 12)head = push(head, 29)head = push(head, 11)head = push(head, 23)head = push(head, 8)prod = 1productAlternateNodes(head, True)print (prod)# This code is contributed by Arnab Kundu |
C#
// C# code to print alternate nodes// of a linked list using recursionusing System; class GFG{ // A linked list nodepublic class Node { public int data; public Node next;};// Inserting node at the beginningstatic Node push(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; return head_ref;}static int prod;// Function to find product of alternate// nodes of linked list.// The boolean flag isOdd is used to find// if the current node is even or odd.static void productAlternateNodes(Node node, bool isOdd){ if (node == null) return; if (isOdd == true) prod = prod * (node.data); productAlternateNodes(node.next, !isOdd);}// Driver codepublic static void Main(String []args){ // Start with the empty list Node head = null; // construct below list // 8 . 23 . 11 . 29 . 12 head = push(head, 12); head = push(head, 29); head = push(head, 11); head = push(head, 23); head = push(head, 8); prod = 1; productAlternateNodes(head, true); Console.WriteLine( prod);}}// This code is contributed by Rajput-Ji |
Javascript
<script>// Javascript code to print alternate nodes// of a linked list using recursionclass Node{ constructor() { this.data = 0; this.next = null; }}// Inserting node at the beginningfunction push(head_ref, new_data){ let new_node = new Node(); new_node.data = new_data; new_node.next = (head_ref); (head_ref) = new_node; return head_ref;}let prod;// Function to find product of alternate// nodes of linked list.// The boolean flag isOdd is used to find// if the current node is even or odd.function productAlternateNodes(node,isOdd){ if (node == null) return; if (isOdd == true) prod = prod * (node.data); productAlternateNodes(node.next, !isOdd);}// Driver code// Start with the empty listlet head = null;// construct below list// 8 . 23 . 11 . 29 . 12head = push(head, 12);head = push(head, 29);head = push(head, 11);head = push(head, 23);head = push(head, 8);prod = 1;productAlternateNodes(head, true);document.write( prod);// This code is contributed by avanitrachhadiya2155</script> |
Output
1056
Complexity Analysis:
- Time Complexity: O(N)
- Auxiliary Space: O(N)
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