Count of Array elements divisible by either their product or sum of digits

Given an array arr[]. The task is to count the elements in the array that are divisible by either their product of digits or the sum of digits.

Example:

Input: arr[] = {123, 25, 36, 7}
Output: 2
Explanation: Following are the elements that follows the given conditions
Sum of digits of 123 is 6 and the product of digits is also 6. 
Since 123 is not divisible by 6, so it is not counted. 
The sum of digits of 36 is 9 and product of digits is 18. Since 36 is divisible by both, so it is considered in answer. 
Similarly, sum of digits and product of digits of 7 is 7 itself, hence it is also considered.
Hence, 2 is the final answer. 

Input: arr[] = {10, 22, 15}
Output: 2
Explanation:  The sum of digits in 10 is 1, and 10 is divisible by 1, hence we consider it. The product of digits of 15 is 5, and 15 is divisible by 5, we consider it in our output.

Approach: This problem is observation-based. Follow the steps below to solve the given problem. 

• Declare a variable say count = 0, to store the number of elements satisfying given conditions.
• For every number in the array arr[], find the sum of its digits and the product of its digits.
• Check whether the number is divisible by either its sum of digits or the product of digits.
• If yes, add it to your count variable.
• Return the count as the final answer.

Below is the implementation of the above approach.

C++

// C++ program for above approach
#include <iostream>
using namespace std;

// Function to find the number of elements
// in arr[] that follows the given conditions
int solve(int arr[], int n)
{

    // To count the number of elements
    // that follow the given conditions
    int count = 0;

    // Iterate through the array arr[]
    for (int i = 0; i < n; i++) {
        int p = arr[i];
        int sum = 0, prod = 1;
        while (p > 0) {
            int r = p % 10;
            sum += r;
            prod *= r;
            p /= 10;
        }

        // Check if condition satisfies or not
        if ((sum > 0 && arr[i] % sum == 0)
            || (prod > 0 && arr[i] % prod == 0))
            count++;
    }

    // Return count as the final answer
    return count;
}

// Driver Code
int main()
{
    int arr[] = { 123, 25, 36, 7 };
    int N = sizeof(arr) / sizeof(arr[0]);

    // Function Call
    cout << solve(arr, N) << endl;

    return 0;
}

Java

// Java program for above approach
import java.util.*;
public class GFG {

  // Function to find the number of elements
  // in arr[] that follows the given conditions
  static int solve(int[] arr, int n)
  {

    // To count the number of elements
    // that follow the given conditions
    int count = 0;

    // Iterate through the array arr[]
    for (int i = 0; i < n; i++) {
      int p = arr[i];
      int sum = 0, prod = 1;
      while (p > 0) {
        int r = p % 10;
        sum += r;
        prod *= r;
        p /= 10;
      }

      // Check if condition satisfies or not
      if ((sum > 0 && arr[i] % sum == 0)
          || (prod > 0 && arr[i] % prod == 0))
        count++;
    }

    // Return count as the final answer
    return count;
  }

  // Driver Code
  public static void main(String args[])
  {
    int[] arr = { 123, 25, 36, 7 };
    int N = arr.length;

    // Function Call
    System.out.println(solve(arr, N));
  }
}

// This code is contributed by Samim Hossain Mondal.

Python3

# python3 program for above approach

# Function to find the number of elements
# in arr[] that follows the given conditions
def solve(arr, n):

        # To count the number of elements
        # that follow the given conditions
    count = 0

    # Iterate through the array arr[]
    for i in range(0, n):
        p = arr[i]
        sum = 0
        prod = 1
        while (p > 0):
            r = p % 10
            sum += r
            prod *= r
            p //= 10

            # Check if condition satisfies or not
        if ((sum > 0 and arr[i] % sum == 0)
                or (prod > 0 and arr[i] % prod == 0)):
            count += 1

        # Return count as the final answer
    return count

# Driver Code
if __name__ == "__main__":

    arr = [123, 25, 36, 7]
    N = len(arr)

    # Function Call
    print(solve(arr, N))

    # This code is contributed by rakeshsahni

C#

// C# program for above approach
using System;
class GFG {

  // Function to find the number of elements
  // in arr[] that follows the given conditions
  static int solve(int[] arr, int n)
  {

    // To count the number of elements
    // that follow the given conditions
    int count = 0;

    // Iterate through the array arr[]
    for (int i = 0; i < n; i++) {
      int p = arr[i];
      int sum = 0, prod = 1;
      while (p > 0) {
        int r = p % 10;
        sum += r;
        prod *= r;
        p /= 10;
      }

      // Check if condition satisfies or not
      if ((sum > 0 && arr[i] % sum == 0)
          || (prod > 0 && arr[i] % prod == 0))
        count++;
    }

    // Return count as the final answer
    return count;
  }

  // Driver Code
  public static void Main()
  {
    int[] arr = { 123, 25, 36, 7 };
    int N = arr.Length;

    // Function Call
    Console.Write(solve(arr, N));
  }
}

// This code is contributed by ukasp.

Javascript

<script>
// Javascript program for above approach

// Function to find the number of elements
// in arr[] that follows the given conditions
function solve(arr, n)
{

    // To count the number of elements
    // that follow the given conditions
    let count = 0;

    // Iterate through the array arr[]
    for (let i = 0; i < n; i++) {
        let p = arr[i];
        let sum = 0, prod = 1;
        while (p > 0) {
            let r = p % 10;
            sum += r;
            prod *= r;
            p = Math.floor(p / 10);
        }

        // Check if condition satisfies or not
        if ((sum > 0 && arr[i] % sum == 0)
            || (prod > 0 && arr[i] % prod == 0))
            count++;
    }

    // Return count as the final answer
    return count;
}

// Driver Code
let arr = [123, 25, 36, 7 ];
let N = arr.length;

    // Function Call
document.write(solve(arr, N));

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

Output

2

Time Complexity: O(N log N) as O(N) takes outer loop and while loop inside it is taking O(Log N) time. 
Auxiliary Space: O(1)