Skip to content
Related Articles

Related Articles

Improve Article

Replace every element of the array by product of all other elements

  • Difficulty Level : Easy
  • Last Updated : 12 May, 2021

Given an array of integers. Replace every element by the product of all other elements of the array.
Examples: 
 

Input : arr[] = { 2, 3, 3, 5, 7 } 
Output : 315 210 210 126 90

Approach : 
 

  • First, take the product of all the element of the array.
  • Now replace each element by the product divided by that element.
  • Print the modified array.

Below is the implementation of above approach:
 

C++




// C++ program to Replace every element
// by the product of all other elements
#include "iostream"
using namespace std;
 
void ReplaceElements(int arr[], int n)
{
    int prod = 1;
 
    // Calculate the product of all the elements
    for (int i = 0; i < n; ++i) {
        prod *= arr[i];
    }
 
    // Replace every element product
    // of all other elements
    for (int i = 0; i < n; ++i) {
        arr[i] = prod / arr[i];
    }
}
 
int main()
{
    int arr[] = { 2, 3, 3, 5, 7 };
    int n = sizeof(arr) / sizeof(arr[0]);
 
    ReplaceElements(arr, n);
 
    // Print the modified array.
    for (int i = 0; i < n; ++i) {
        cout << arr[i] << " ";
    }
    return 0;
}

Java




// Java program to Replace every element
// by the product of all other elements
 
class GFG{
static void ReplaceElements(int arr[], int n)
{
    int prod = 1;
 
    // Calculate the product of all the elements
    for (int i = 0; i < n; ++i) {
        prod *= arr[i];
    }
 
    // Replace every element product
    // of all other elements
    for (int i = 0; i < n; ++i) {
        arr[i] = prod / arr[i];
    }
}
 
public static void main(String[] args)
{
    int arr[] = { 2, 3, 3, 5, 7 };
    int n = arr.length;
 
    ReplaceElements(arr, n);
 
    // Print the modified array.
    for (int i = 0; i < n; ++i) {
        System.out.print(arr[i]+" ");
    }
    System.out.println("");
 
}
}
// This code is contributed by mits

Python 3




# Python 3 program to Replace every
# element by the product of all
# other elements
 
def ReplaceElements(arr, n):
    prod = 1
 
    # Calculate the product of
    # all the elements
    for i in range(n):
        prod *= arr[i]
 
    # Replace every element product
    # of all other elements
    for i in range(n) :
        arr[i] = prod // arr[i]
 
# Driver Code
if __name__ == "__main__":
    arr = [ 2, 3, 3, 5, 7 ]
    n = len(arr)
 
    ReplaceElements(arr, n)
 
    # Print the modified array.
    for i in range( n):
        print(arr[i], end = " ")
 
# This code is contributed
# by ChitraNayal

C#




// C# program to Replace every element
// by the product of all other elements
using System;
 
class GFG
{
static void ReplaceElements(int []arr, int n)
{
    int prod = 1;
 
    // Calculate the product of
    // all the elements
    for (int i = 0; i < n; ++i)
    {
        prod *= arr[i];
    }
 
    // Replace every element product
    // of all other elements
    for (int i = 0; i < n; ++i)
    {
        arr[i] = prod / arr[i];
    }
}
 
// Driver Code
static public void Main ()
{
    int []arr = { 2, 3, 3, 5, 7 };
    int n = arr.Length;
     
    ReplaceElements(arr, n);
     
    // Print the modified array.
    for (int i = 0; i < n; ++i)
    {
        Console.Write(arr[i]+" ");
    }
    Console.WriteLine("");
}
}
 
// This code is contributed by ajit

PHP




<?php
// PHP program to Replace every element
// by the product of all other elements
 
function ReplaceElements($arr, $n)
{
    $prod = 1;
 
    // Calculate the product of all
    // the elements
    for ($i = 0; $i < $n; ++$i)
    {
        $prod *= $arr[$i];
    }
 
    // Replace every element product
    // of all other elements
    for ($i = 0; $i < $n; ++$i)
    {
        $arr[$i] = (int)($prod / $arr[$i]);
    }
    return $arr;
}
 
// Driver Code
$arr = array( 2, 3, 3, 5, 7 );
$n = sizeof($arr);
 
$arr1 = ReplaceElements($arr, $n);
 
// Print the modified array.
for ($i = 0; $i < $n; ++$i)
{
    echo $arr1[$i] . " ";
}
 
// This code is contributed
// by Akanksha Rai
?>

Javascript




<script>
    // Javascript program to Replace every element
    // by the product of all other elements
     
    function ReplaceElements(arr, n)
    {
        let prod = 1;
 
        // Calculate the product of
        // all the elements
        for (let i = 0; i < n; ++i)
        {
            prod *= arr[i];
        }
 
        // Replace every element product
        // of all other elements
        for (let i = 0; i < n; ++i)
        {
            arr[i] = parseInt(prod / arr[i], 10);
        }
    }
     
    let arr = [ 2, 3, 3, 5, 7 ];
    let n = arr.length;
       
    ReplaceElements(arr, n);
       
    // Print the modified array.
    for (let i = 0; i < n; ++i)
    {
        document.write(arr[i]+" ");
    }
 
</script>

Output : 
 

315 210 210 126 90

Time Complexity – O(N)
 

Attention reader! Don’t stop learning now. Get hold of all the important mathematical concepts for competitive programming with the Essential Maths for CP Course at a student-friendly price. To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.




My Personal Notes arrow_drop_up
Recommended Articles
Page :