Smallest number greater than or equal to X whose sum of digits is divisible by Y

Given two integers X and Y, the task is to find the smallest number greater than or equal to X whose sum of digits is divisible by Y. 
Note: 1 <= X <= 1000, 1 <= Y <= 50.
Examples:

Input: X = 10, Y = 5 
Output: 14 
Explanation:
14 is the smallest number greater than 10 whose sum of digits (1+4 = 5) is divisible by 5. 
Input: X = 5923, Y = 13 
Output: 5939 

Approach: The idea for this problem is to run a loop from X and check for each integer if its sum of digits is divisible by Y or not. Return the first number whose sum of digits is divisible by Y. Given the constraints of X and Y, the answer always exist. 
Below is the implementation of the above approach: 

C++

// C++ program to find the smallest number greater than or
// equal to X and divisible by Y

#include <bits/stdc++.h>
using namespace std;

#define MAXN 10000000

// Function that returns the sum of digits of a number
int sumOfDigits(int n)
{
    // Initialize variable to store the sum
    int sum = 0;
    while (n > 0) {
        // Add the last digit of the number
        sum += n % 10;
        // Remove the last digit from the number
        n /= 10;
    }
    return sum;
}

// Function that returns the smallest number greater than or
// equal to X and divisible by Y
int smallestNum(int X, int Y)
{
    // Initialize result variable
    int res = -1;
    // Loop through numbers greater than  equal to X
    for (int i = X; i < MAXN; i++) {
        // Calculate sum of digits
        int sum_of_digit = sumOfDigits(i);
        // Check if sum of digits is divisible by Y
        if (sum_of_digit % Y == 0) {
            res = i;
            break;
        }
    }
    return res;
}

// Driver code
int main()
{
    int X = 5923, Y = 13;
    cout << smallestNum(X, Y);
    return 0;
}

// This code is contributed by Sania Kumari Gupta

C

// C program to find the smallest number greater than or
// equal to X and divisible by Y
#include <stdio.h>

#define MAXN 10000000

// Function that returns the sum of digits of a number
int sumOfDigits(int n)
{
    // Initialize variable to store the sum
    int sum = 0;
    while (n > 0) {
        // Add the last digit of the number
        sum += n % 10;
        // Remove the last digit from the number
        n /= 10;
    }
    return sum;
}

// Function that returns the smallest number greater than or
// equal to X and divisible by Y
int smallestNum(int X, int Y)
{
    // Initialize result variable
    int res = -1;
    // Loop through numbers greater than  equal to X
    for (int i = X; i < MAXN; i++) {
        // Calculate sum of digits
        int sum_of_digit = sumOfDigits(i);
        // Check if sum of digits is divisible by Y
        if (sum_of_digit % Y == 0) {
            res = i;
            break;
        }
    }
    return res;
}

// Driver code
int main()
{
    int X = 5923, Y = 13;
    printf("%d", smallestNum(X, Y));
    return 0;
}

// This code is contributed by Sania Kumari Gupta

Java

// Java program to find the smallest number
// greater than or equal to X and divisible by Y

class GFG{

static final int MAXN = 10000000;

// Function that returns the sum
// of digits of a number
static int sumOfDigits(int n)
{

    // Initialize variable to
    // store the sum
    int sum = 0;
    while (n > 0)
    {

         // Add the last digit
         // of the number
         sum += n % 10;

         // Remove the last digit
         // from the number
         n /= 10;
    }
    return sum;
}

// Function that returns the smallest number
// greater than or equal to X and divisible by Y
static int smallestNum(int X, int Y)
{

    // Initialize result variable
    int res = -1;

    // Loop through numbers greater
    // than equal to X
    for (int i = X; i < MAXN; i++)
    {

        // Calculate sum of digits
        int sum_of_digit = sumOfDigits(i);

        // Check if sum of digits
        // is divisible by Y
        if (sum_of_digit % Y == 0)
        {
            res = i;
            break;
        }
    }
    return res;
}

// Driver code
public static void main(String[] args)
{
    int X = 5923, Y = 13;
    System.out.print(smallestNum(X, Y));
}
}

// This code is contributed by Rohit_ranjan

Python3

# Python3 program to find the smallest number
# greater than or equal to X and divisible by Y

MAXN = 10000000

# Function that returns the
# sum of digits of a number
def sumOfDigits(n):

    # Initialize variable
    # to store the sum
    sum = 0

    while(n > 0):

        # Add the last digit
        # of the number
        sum += n % 10

        # Remove the last digit
        # from the number
        n //= 10

    return sum

# Function that returns the smallest number
# greater than or equal to X and divisible by Y
def smallestNum(X, Y):

    # Initialize result variable
    res = -1;

    # Loop through numbers greater
    # than equal to X
    for i in range(X, MAXN):

        # Calculate sum of digits
        sum_of_digit = sumOfDigits(i)

        # Check if sum of digits
        # is divisible by Y
        if sum_of_digit % Y == 0:
            res = i
            break

    return res

# Driver code
if __name__=='__main__':

    (X, Y) = (5923, 13)

    print(smallestNum(X, Y))

# This code is contributed by rutvik_56

C#

// C# program to find the smallest number
// greater than or equal to X and divisible by Y
using System;

class GFG{

static readonly int MAXN = 10000000;

// Function that returns the sum
// of digits of a number
static int sumOfDigits(int n)
{

    // Initialize variable to
    // store the sum
    int sum = 0;
    while(n > 0)
    {

         // Add the last digit
         // of the number
         sum += n % 10;

         // Remove the last digit
         // from the number
         n /= 10;
    }
    return sum;
}

// Function that returns the smallest number
// greater than or equal to X and divisible by Y
static int smallestNum(int X, int Y)
{

    // Initialize result variable
    int res = -1;

    // Loop through numbers greater
    // than equal to X
    for(int i = X; i < MAXN; i++)
    {

        // Calculate sum of digits
        int sum_of_digit = sumOfDigits(i);

        // Check if sum of digits
        // is divisible by Y
        if(sum_of_digit % Y == 0)
        {
           res = i;
           break;
        }
    }
    return res;
}

// Driver code
public static void Main(String[] args)
{
    int X = 5923, Y = 13;
    Console.Write(smallestNum(X, Y));
}
}

// This code is contributed by gauravrajput1

Javascript

<script>

// javascript program to find the smallest number
// greater than or equal to X and divisible by Y
var MAXN = 10000000;

// Function that returns the sum
// of digits of a number
function sumOfDigits(n)
{

    // Initialize variable to
    // store the sum
    var sum = 0;
    while (n > 0)
    {

         // Add the last digit
         // of the number
         sum += n % 10;

         // Remove the last digit
         // from the number
         n  = parseInt(n/10);
    }
    return sum;
}

// Function that returns the smallest number
// greater than or equal to X and divisible by Y
function smallestNum(X , Y)
{

    // Initialize result variable
    var res = -1;

    // Loop through numbers greater
    // than equal to X
    for (i = X; i < MAXN; i++)
    {

        // Calculate sum of digits
        var sum_of_digit = sumOfDigits(i);

        // Check if sum of digits
        // is divisible by Y
        if (sum_of_digit % Y == 0)
        {
            res = i;
            break;
        }
    }
    return res;
}

// Driver code
var X = 5923, Y = 13;
document.write(smallestNum(X, Y));


// This code contributed by shikhasingrajput
</script>

Output:

5939

Time Complexity: O(MAXN)

Auxiliary Space: O(1)