Program for multiplication of array elements

We are given an array, and we have to calculate the product of an array using both iterative and recursive methods. 

Examples:

Input : array[] = {1, 2, 3, 4, 5, 6}
Output : 720
Here, product of elements = 1*2*3*4*5*6 = 720

Input : array[] = {1, 3, 5, 7, 9}
Output : 945 

Iterative Method: We initialize result as 1. We traverse array from left to right and multiply elements with results. 

Implementation:

C++

// Iterative C++ program to
// multiply array elements
#include<bits/stdc++.h>

using namespace std;

// Function to calculate the
// product of the array
int multiply(int array[], int n)
{
    int pro = 1;
    for (int i = 0; i < n; i++)
        pro = pro * array[i];
    return pro;
}

// Driver Code
int main()
{
    int array[] = {1, 2, 3, 4, 5, 6};
    int n = sizeof(array) / sizeof(array[0]);

    // Function call to calculate product
    cout << multiply(array, n);
    return 0;
}

Java

// Iterative Java program to
// multiply array elements
import java.io.*;
public class GFG
{
    static int arr[] = {1, 2, 3, 4, 5, 6};

    // Method to calculate the
    // product of the array
    static int multiply()
    {
        int pro = 1;
        for (int i = 0; i < arr.length; i++)
            pro = pro * arr[i];
        return pro;
    }

    // Driver Code
    public static void main(String[] args)
    {
        // Method call to calculate product
        System.out.println(multiply());
        }
}

Python3

# Iterative Python3 code to
# multiply list elements

# Function to calculate
# the product of the array
def multiply( array , n ):
    pro = 1
    for i in range(n):
        pro = pro * array[i]
    return pro

# Driver code
array = [1, 2, 3, 4, 5, 6]
n = len(array)

# Function call to
# calculate product
print(multiply(array, n))

# This code is contributed
# by "Sharad_Bhardwaj".

C#

// Iterative C# program to
// multiply array elements
using System;

class GFG
{
    static int []arr = {1, 2, 3, 4, 5, 6};

    // Method to calculate the
    // product of the array
    static int multiply()
    {
        int pro = 1;
        for (int i = 0; i < arr.Length; i++)
            pro = pro * arr[i];
        return pro;
    }

    // Driver Code
    public static void Main()
    {
        // Method call to calculate product
        Console.Write(multiply());
    }
}

// This code is contributed by nitin mittal

PHP

<?php
// Iterative PHP program to
// multiply array elements


// Function to calculate the
// product of the array
function multiply($arr, $n)
{
    $pro = 1;
    for ($i = 0; $i < $n; $i++)
        $pro = $pro * $arr[$i];
    return $pro;
}

// Driver Code
$arr = array(1, 2, 3, 4, 5, 6);
$n = sizeof($arr) / sizeof($arr[0]);

// Function call to
// calculate product
echo multiply($arr, $n);
return 0;

// This code is contributed by nitin mittal.
?>

Javascript

<script>

// Iterative javascript program to
// multiply array elements

    var arr = [ 1, 2, 3, 4, 5, 6 ];

    // Method to calculate the
    // product of the array
    function multiply() {
        var pro = 1;
        for (i = 0; i < arr.length; i++)
            pro = pro * arr[i];
        return pro;
    }

    // Driver Code

        // Method call to calculate product
        document.write(multiply());

// This code contributed by aashish1995

</script>

Output

720

Time Complexity: O(n)
Auxiliary Space: O(1)

Recursive Method:

C++

// Recursive C++ program to
// multiply array elements
#include<iostream>

using namespace std;

// Function to calculate the
// product of array using recursion
int multiply(int a[], int n)
{
    // Termination condition
    if (n == 0)
        return(a[n]);
    else
        return (a[n] * multiply(a, n - 1));
}

// Driver Code
int main()
{
    int array[] = {1, 2, 3, 4, 5, 6};
    int n = sizeof(array) / sizeof(array[0]);

    // Function call to
    // calculate the product
    cout << multiply(array, n - 1)
         << endl;
    return 0;
}

Java

// Recursive Java program to
// multiply array elements
import java.io.*;
public class GFG
{
    static int arr[] = {1, 2, 3, 4, 5, 6};

    // Method to calculate the product
    // of the array using recursion
    static int multiply(int a[], int n)
    {
        // Termination condition
        if (n == 0)
            return(a[n]);
        else
            return (a[n] * multiply(a, n - 1));
    }

    // Driver Code
    public static void main(String[] args)
    {
        // Method call to
        // calculate product
        System.out.println(multiply(arr,
                       arr.length - 1));
        }
}

Python3

# Recursive Python3 code
# to multiply array elements

# Function to calculate the product
# of array using recursion
def multiply( a , n ):

    # Termination condition
    if n == 0:
        return(a[n])
    else:
        return (a[n] * multiply(a, n - 1))

# Driver Code
array = [1, 2, 3, 4, 5, 6]
n = len(array)

# Function call to
# calculate the product
print(multiply(array, n - 1))

# This code is contributed
# by "Sharad_Bhardwaj".

C#

// Recursive C# program to
// multiply array elements
using System;

class GFG
{

    static int []arr = {1, 2, 3, 4, 5, 6};

    // Method to calculate the product
    // of the array using recursion
    static int multiply(int []a, int n)
    {

        // Termination condition
        if (n == 0)
            return(a[n]);
        else
            return (a[n] * multiply(a, n - 1));
    }

    // Driver Code
    public static void Main()
    {

        // Method call to
        // calculate product
        Console.Write(multiply(arr,
                               arr.Length - 1));
    }
}

// This code is contributed by Nitin Mittal.

PHP

<?php
// Recursive PHP program to
// multiply array elements

// Function to calculate the
// product of array using recursion
function multiply( $a, $n)
{
    // Termination condition
    if ($n == 0)
        return($a[$n]);
    else
        return ($a[$n] *
                 multiply($a, $n - 1));
}

// Driver Code
$array = array(1, 2, 3, 4, 5, 6);
$n = count($array);

// Function call to
// calculate the product
echo multiply($array, $n - 1)

// This code is contributed by anuj_67.
?>

Javascript

<script>
// Recursive javascript program to
// multiply array elements

    var arr = [ 1, 2, 3, 4, 5, 6 ];

    // Method to calculate the product
    // of the array using recursion
    function multiply(a , n) {
        // Termination condition
        if (n == 0)
            return (a[n]);
        else
            return (a[n] * multiply(a, n - 1));
    }

    // Driver Code

        // Method call to
        // calculate product
        document.write(multiply(arr,
                       arr.length - 1));

// This code is contributed by todaysgaurav
</script>

Output

720

Time Complexity: O(n)
Auxiliary Space: O(n)

Using Library functions:

C++

// C++ program for multiplication of array elements
#include <iostream>
/*In C++, we can quickly find array product using
accumulate() and multiplies<>() defined in numeric library*/
#include <numeric>

using namespace std;

// Function to calculate the
// product of the array
int multiply(int array[], int n)
{
    // The pro specifies the initial value to be considered
    int pro = 1;
    /*
    Here accumulate() take 4 parameters:
    begening of array, end of array, the initial value
    and the binary operation function object that will be
    applied
    */
    return accumulate(array, array + n, pro,
                      multiplies<int>());
}

int main()
{
    int array[] = { 1, 2, 3, 4, 5, 6 };
    // get length of array
    int n = sizeof(array) / sizeof(array[0]);
    cout << multiply(array, n);
    return 0;
    // This code is contributed by Shivesh Kumar Dwivedi
}

Java

// Java program for multiplication of array elements
import java.util.Arrays;
import java.util.function.IntBinaryOperator;

public class GFG {

    // Function to calculate the product of the array
    public static int multiply(int[] array)
    {

        // The pro specifies the initial value to be
        // considered
        int pro = 1;
        /*
            Here Arrays.stream() method is used to get an
           IntStream of array, then reduce() method is used
           with the help of IntBinaryOperator interface and
           multiplies operation to perform the binary
           operation between the array elements and the
           initial value.
            */
        return Arrays.stream(array).reduce(
            pro, new IntBinaryOperator() {
                @Override
                public int applyAsInt(int left, int right)
                {
                    return left * right;
                }
            });
    }

    public static void main(String[] args)
    {
        int[] array = { 1, 2, 3, 4, 5, 6 };

        // get length of array
        int n = array.length;
        System.out.println(multiply(array));
    }
}

// this code is contributed by bhardwajji

Python3

# python3 program for multiplication of array elements

# In python3, we can quickly find array product using
# reduce available in functools library
from functools import reduce

# Function to calculate the
# product of the array


def multiply(array, n):

    # The reduce() only takes the name of the array/list as a parameter
    return reduce((lambda x, y: x * y), array)


array = [1, 2, 3, 4, 5, 6]
# get length of array
n = len(array)
print(multiply(array, n))

# This code is contributed by Abhijeet Kumar(abhijeet19403)

C#

// C# program for multiplication of array elements
using System;

// In C#, we can quickly find array
// product using using the Aggregate
// method from the System.Linq namespace
using System.Linq;

public class GFG {

    // Function to calculate the product of the array
    static int Multiply(int[] array, int n)
    {

        // The pro specifies the initial value to be
        // considered
        int pro = 1;

        // here Aggregate method takes two arguments
        // an initial value (in this case, pro) and a
        // delegate function that defines how to
        // aggregate the values in the array
        return array.Aggregate(pro, (current, t) =
                                        > current * t);
    }

    // Driver Code
    static public void Main(string[] args)
    {
        int[] array = { 1, 2, 3, 4, 5, 6 };

        // get length of array
        int n = array.Length;
        Console.WriteLine(Multiply(array, n));
    }
}

// This code is contributed by Prasad Kandekar(prasad264)

Javascript

<script>
  // Function to calculate the product of the array
  function multiply(array) {
    // The pro specifies the initial value to be considered
    let pro = 1;
    /*
        Here the reduce() method is used with the help of an arrow function to perform the binary operation between
        the array elements and the initial value.
    */
    return array.reduce((acc, cur) => acc * cur, pro);
  }

  let array = [1, 2, 3, 4, 5, 6];

  // get length of array
  let n = array.length;
  console.log(multiply(array));
</script>

Output

720

Time Complexity: O(n)
Auxiliary Space: O(1)