# Sum of the products of same placed digits of two numbers

Given two positive integers N1 and N2, the task is to find the sum of the products of the same placed digits of the two numbers.
Note: For numbers of unequal length, the preceding digits of the smaller number needs to be treated as 0.

Examples:

Input: N1 = 5, N2 = 67
Output: 35
Explanation:
At one’s place, we have digits 5 and 7, their product is 35. At ten’s place we have 6 in N2. As N1 has no digit at ten’s place, 6 will be multiplied with 0, leading to no effect on the sum. Hence, the calculated sum is 35.

Input: N1 = 25, N2 = 1548
Output: 48
Explanation:
Sum = 5 * 8 + 2 * 4 + 0 * 5 + 0 * 1 = 48.

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach:
To solve the problem mentioned above, we need to follow the steps below:

• Extract the rightmost digits of the two numbers and multiply them and add their product to sum.
• Now remove the digit.
• Keep repeating the above two steps until one of them is reduced to 0. Then, print the final value of sum calculated.

Below is the implementation of the above approach:

## C++

 `// C++ program to calculate the  ` `// sum of same placed digits  ` `// of two numbers ` `#include ` `using` `namespace` `std; ` ` `  `int` `sumOfProductOfDigits(``int` `n1, ``int` `n2) ` `{ ` `    ``int` `sum = 0; ` `     `  `    ``// Loop until one of the numbers ` `    ``// have no digits remaining ` `    ``while` `(n1 > 0 && n2 > 0)  ` `    ``{ ` `        ``sum += ((n1 % 10) * (n2 % 10)); ` `        ``n1 /= 10; ` `        ``n2 /= 10; ` `    ``} ` `    ``return` `sum; ` `} ` ` `  `// Driver Code ` `int` `main() ` `{ ` `    ``int` `n1 = 25; ` `    ``int` `n2 = 1548; ` ` `  `    ``cout << sumOfProductOfDigits(n1, n2); ` `} ` ` `  `// This code is contributed by grand_master `

## Java

 `// Java program to calculate the ` `// sum of same placed digits of ` `// two numbers ` ` `  `class` `GFG { ` ` `  `    ``// Function to find the sum of the ` `    ``// products of their corresponding digits ` `    ``static` `int` `sumOfProductOfDigits(``int` `n1, ` `                                    ``int` `n2) ` `    ``{ ` `        ``int` `sum = ``0``; ` `        ``// Loop until one of the numbers ` `        ``// have no digits remaining ` `        ``while` `(n1 > ``0` `&& n2 > ``0``) { ` `            ``sum += ((n1 % ``10``) * (n2 % ``10``)); ` `            ``n1 /= ``10``; ` `            ``n2 /= ``10``; ` `        ``} ` ` `  `        ``return` `sum; ` `    ``} ` ` `  `    ``// Driver Code ` `    ``public` `static` `void` `main(String args[]) ` `    ``{ ` ` `  `        ``int` `n1 = ``25``; ` `        ``int` `n2 = ``1548``; ` ` `  `        ``System.out.println( ` `            ``sumOfProductOfDigits(n1, n2)); ` `    ``} ` `} `

## Python3

 `# Python3 program to calculate the  ` `# sum of same placed digits  ` `# of two numbers ` ` `  `def` `sumOfProductOfDigits(n1, n2): ` ` `  `    ``sum1 ``=` `0``; ` `     `  `    ``# Loop until one of the numbers ` `    ``# have no digits remaining ` `    ``while` `(n1 > ``0` `and` `n2 > ``0``): ` ` `  `        ``sum1 ``+``=` `((n1 ``%` `10``) ``*` `(n2 ``%` `10``)); ` `        ``n1 ``=` `n1 ``/``/` `10``; ` `        ``n2 ``=` `n2 ``/``/` `10``; ` `         `  `    ``return` `sum1; ` ` `  `# Driver Code ` `n1 ``=` `25``; ` `n2 ``=` `1548``; ` ` `  `print``(sumOfProductOfDigits(n1, n2)); ` ` `  `# This code is contributed by Nidhi_biet `

## C#

 `// C# program to calculate the ` `// sum of same placed digits of ` `// two numbers ` `using` `System; ` `class` `GFG{ ` ` `  `// Function to find the sum of the ` `// products of their corresponding digits ` `static` `int` `sumOfProductOfDigits(``int` `n1, ` `                                ``int` `n2) ` `{ ` `    ``int` `sum = 0; ` `     `  `    ``// Loop until one of the numbers ` `    ``// have no digits remaining ` `    ``while` `(n1 > 0 && n2 > 0)  ` `    ``{ ` `        ``sum += ((n1 % 10) * (n2 % 10)); ` `        ``n1 /= 10; ` `        ``n2 /= 10; ` `    ``} ` `    ``return` `sum; ` `} ` ` `  `// Driver Code ` `public` `static` `void` `Main() ` `{ ` `    ``int` `n1 = 25; ` `    ``int` `n2 = 1548; ` ` `  `    ``Console.WriteLine( ` `            ``sumOfProductOfDigits(n1, n2)); ` `} ` `} ` ` `  `// This code is contributed by 29AjayKumar `

Output:

```48
```

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.

My Personal Notes arrow_drop_up External Technical Content Reviewer at GeeksforGeeks

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.