harshadnumbers

Harshad Numbers

ID: harshadnumbers

Difficulty: 1.4

CPU Time: 1 second

Memory: 1024 MB

Solution

Making a helper function to compute the sum of the digits of a number can be helpful. A recursive identity to calculate this sum of a number x can be (x % 10) + sumOfDigits(x / 10), and the divisibility described implies that x % sumOfDigits(x) == 0, so one can simply run a loop starting at the given number n, and until this condition (n % sumOfDigits(n) == 0) is true, increment n. After this loop is done, output n.