Product of all pairwise consecutive elements in an Array

Given an array of integers of N elements. The task is to print the product of all of the pairwise consecutive elements.
Pairwise consecutive pairs of an array of size N are (a[i], a[i+1]) for all ranging from 0 to N-2

Examples: 

Input  : arr[] = {8, 5, 4, 3, 15, 20}
Output : 40, 20, 12, 45, 300

Input  : arr[] = {5, 10, 15, 20}
Output : 50, 150, 300

The solution is to traverse the array and calculate and print the product of every pair (arr[i], arr[i+1]).

Below is the implementation of this approach: 

C++

// C++ program to print the
// product of the consecutive elements.
#include <iostream>
using namespace std;

// Function to print pairwise
// consecutive product
void pairwiseProduct(int arr[], int n)
{
    int prod = 1;
    for (int i = 0; i < n - 1; i++) {

        // multiply the alternate numbers
        prod = arr[i] * arr[i + 1];
        printf(" %d ", prod);
    }
}

// Driver Code
int main()
{
    int arr[] = { 4, 10, 15, 5, 6 };
    int n = sizeof(arr) / sizeof(arr[0]);

    pairwiseProduct(arr, n);

    return 0;
}

C

// C program to print the
// product of the consecutive elements.
#include <stdio.h>

// Function to print pairwise
// consecutive product
void pairwiseProduct(int arr[], int n)
{
    int prod = 1;
    for (int i = 0; i < n - 1; i++) {

        // multiply the alternate numbers
        prod = arr[i] * arr[i + 1];
        printf(" %d ", prod);
    }
}

// Driver Code
int main()
{
    int arr[] = { 4, 10, 15, 5, 6 };
    int n = sizeof(arr) / sizeof(arr[0]);

    pairwiseProduct(arr, n);

    return 0;
}

// This code is contributed by kothavvsaakash.

Java

// Java program to print the product
// of the consecutive elements.
import java .io.*;

class GFG
{
// Function to print pairwise
// consecutive product
static void pairwiseProduct(int[] arr,
                            int n)
{
    int prod = 1;
    for (int i = 0; i < n - 1; i++)
    {

        // multiply the alternate numbers
        prod = arr[i] * arr[i + 1];
        System.out.print(prod + " ");
    }
}

// Driver Code
public static void main(String[] args)
{
    int[] arr = { 4, 10, 15, 5, 6 };
    int n = arr.length;

    pairwiseProduct(arr, n);
}
}

// This code is contributed
// by anuj_67..

Python 3

# Python 3 program to print the
# product of the consecutive elements.

# Function to print pairwise
# consecutive product
def pairwiseProduct( arr, n):

    prod = 1
    for i in range(n - 1) :

        # multiply the alternate numbers
        prod = arr[i] * arr[i + 1]
        print(prod, end = " ")

# Driver Code
if __name__=="__main__":

    arr = [ 4, 10, 15, 5, 6 ]
    n = len(arr)

    pairwiseProduct(arr, n)

# This code is contributed
# by ChitraNayal

C#

// C# program to print the product
// of the consecutive elements.
using System;

class GFG
{
// Function to print pairwise
// consecutive product
static void pairwiseProduct(int[] arr,
                            int n)
{
    int prod = 1;
    for (int i = 0; i < n - 1; i++)
    {

        // multiply the alternate numbers
        prod = arr[i] * arr[i + 1];
        Console.Write(prod + " ");
    }
}

// Driver Code
public static void Main()
{
    int[] arr = { 4, 10, 15, 5, 6 };
    int n = arr.Length;

    pairwiseProduct(arr, n);
}
}

// This code is contributed
// by Akanksha Rai(Abby_akku)

PHP

<?php
// PHP program to print the
// product of the consecutive elements.

// Function to print pairwise
// consecutive product
function pairwiseProduct(&$arr, $n)
{
    $prod = 1;
    for ($i = 0; $i < $n - 1; $i++)
    {

        // multiply the alternate numbers
        $prod = $arr[$i] * $arr[$i + 1];
        echo ($prod);
        echo (" ");
    }
}

// Driver Code
$arr = array(4, 10, 15, 5, 6 );
$n = sizeof($arr);

pairwiseProduct($arr, $n);

// This code is contributed
// by Shivi_Aggarwal
?>

Javascript

<script>

// Javascript program to print the
// product of the consecutive elements.

// Function to print pairwise
// consecutive product
function pairwiseProduct( arr,  n)
{
    let prod = 1;
    for (let i = 0; i < n - 1; i++) {

        // multiply the alternate numbers
        prod = arr[i] * arr[i + 1];
        document.write(prod + " ");;
    }
}

    // driver code
    let arr = [ 4, 10, 15, 5, 6 ];
    let n = arr.length;
    pairwiseProduct(arr, n);

   // This code is contributed by jana_sayantan.
</script>

Output

 40  150  75  30 

Time Complexity: O(n), where n is the length of the given array
Auxiliary Space: O(1), As constant extra space is used.